Make #[dom_struct] a proc_macro attribute

[nox]

The rustup is needed for rust-lang/rust#40039.

---

This change is 

[highfive]

Heads up! This PR modifies the following files:

• @KiChjang: components/script/dom/request.rs, components/script/dom/workerlocation.rs, components/script/dom/xmldocument.rs, components/script/dom/svgelement.rs, components/script/dom/dompoint.rs, components/script/dom/webglframebuffer.rs, components/script/dom/crypto.rs, components/script/dom/client.rs, components/script/dom/focusevent.rs, components/script/dom/vrdisplaycapabilities.rs, components/script/dom/dissimilaroriginlocation.rs, components/script/dom/csskeyframesrule.rs, components/script/dom/htmlcanvaselement.rs, components/script/dom/blob.rs, components/script/dom/location.rs, components/script_plugins/jstraceable.rs, components/script/dom/htmldivelement.rs, components/script/dom/eventtarget.rs, components/script/dom/popstateevent.rs, components/script/dom/htmlfieldsetelement.rs, components/script/dom/htmlformcontrolscollection.rs, components/script/dom/workerglobalscope.rs, components/script/dom/pluginarray.rs, components/script/dom/imagedata.rs, components/script/dom/bluetoothpermissionresult.rs, components/script/dom/domstringmap.rs, components/script/dom/bindings/iterable.rs, components/script/dom/htmlpreelement.rs, components/script/dom/file.rs, components/script/dom/webglbuffer.rs, components/script/dom/htmlheadelement.rs, components/script/dom/svgsvgelement.rs, components/script/dom/htmlmapelement.rs, components/script/Cargo.toml, components/script/dom/keyboardevent.rs, components/script/dom/htmldetailselement.rs, components/script/dom/urlsearchparams.rs, components/script/dom/htmldialogelement.rs, components/script/dom/htmloptgroupelement.rs, components/script/dom/htmlimageelement.rs, components/script/dom/css.rs, components/script/dom/promise.rs, components/script/dom/worker.rs, components/script/dom/attr.rs, components/script/dom/htmlbuttonelement.rs, components/script/dom/svggraphicselement.rs, components/script/dom/webglrenderbuffer.rs, components/script/dom/globalscope.rs, components/script/dom/domrectreadonly.rs, components/script/dom/event.rs, components/script/dom/radionodelist.rs, components/script/dom/webglshader.rs, components/script/dom/htmldataelement.rs, components/script/dom/htmlanchorelement.rs, components/script/dom/node.rs, components/script/dom/workernavigator.rs, components/script/dom/serviceworkercontainer.rs, components/script/dom/canvasgradient.rs, components/script/dom/documentfragment.rs, components/script/dom/htmltableelement.rs, components/script/dom/htmltablesectionelement.rs, components/script/dom/progressevent.rs, components/script/dom/textdecoder.rs, components/script/dom/canvaspattern.rs, components/script/dom/htmldatalistelement.rs, components/script/dom/cssfontfacerule.rs, components/script/dom/dommatrix.rs, components/script/dom/bluetoothcharacteristicproperties.rs, components/script/dom/mouseevent.rs, components/script/dom/touchevent.rs, components/script/dom/range.rs, components/script/dom/testbindingproxy.rs, components/script/dom/htmlulistelement.rs, components/script/dom/htmlselectelement.rs, components/script/dom/pagetransitionevent.rs, components/script/dom/bluetoothuuid.rs, components/script/dom/htmldlistelement.rs, components/script/dom/processinginstruction.rs, components/script/dom/domrect.rs, components/script/dom/bluetoothdevice.rs, components/script/dom/htmlparamelement.rs, components/script/dom/htmldirectoryelement.rs, components/script/dom/htmllinkelement.rs, components/script/dom/performance.rs, components/script/dom/testbinding.rs, components/script/dom/cssstyledeclaration.rs, components/script/dom/webglrenderingcontext.rs, components/script/dom/browsingcontext.rs, components/script/dom/messageevent.rs, components/script/dom/webglcontextevent.rs, components/script/dom/xmlhttprequest.rs, components/script/dom/htmllielement.rs, components/script/dom/htmlmeterelement.rs, components/script/dom/serviceworker.rs, components/script/dom/bluetoothadvertisingevent.rs, components/script/dom/htmlmediaelement.rs, components/script/dom/customevent.rs, components/script/dom/htmltablecellelement.rs, components/script/dom/servoparser/mod.rs, components/script/dom/uievent.rs, components/script/dom/extendableevent.rs, components/script/dom/history.rs, components/script/dom/vrdisplayevent.rs, components/script/dom/testbindingpairiterable.rs, components/script/dom/htmlmodelement.rs, components/script/dom/stylesheet.rs, components/script/dom/namednodemap.rs, components/script/dom/mediaquerylistevent.rs, components/script/dom/domrectlist.rs, components/script/dom/touch.rs, components/script/dom/htmlinputelement.rs, components/script/dom/response.rs, components/script/dom/csssupportsrule.rs, components/script/dom/domimplementation.rs, components/script/dom/htmlareaelement.rs, components/script/dom/htmlsourceelement.rs, components/script/dom/htmltrackelement.rs, components/script/dom/htmlframeelement.rs, components/script/dom/serviceworkerregistration.rs, components/script/dom/domtokenlist.rs, components/script/dom/webglprogram.rs, components/script/dom/plugin.rs, components/script/dom/mimetype.rs, components/script/dom/htmlolistelement.rs, components/script/dom/xmlhttprequestupload.rs, components/script/dom/eventsource.rs, components/script/dom/closeevent.rs, components/script/dom/cssstylesheet.rs, components/script/dom/domexception.rs, components/script/dom/htmlhrelement.rs, components/script/dom/htmlprogresselement.rs, components/script/dom/htmltablecolelement.rs, components/script/dom/bluetoothremotegattdescriptor.rs, components/script/dom/htmlcollection.rs, components/script/dom/treewalker.rs, components/script/dom/nodeiterator.rs, components/script/dom/htmlmetaelement.rs, components/script/dom/vr.rs, components/script/dom/filereader.rs, components/script/dom/dissimilaroriginwindow.rs, components/script/dom/beforeunloadevent.rs, components/script/dom/htmltabledatacellelement.rs, components/script/dom/vrpose.rs, components/script/dom/webgluniformlocation.rs, components/script/dom/hashchangeevent.rs, components/script/dom/htmltitleelement.rs, components/script/dom/bluetoothremotegattserver.rs, components/script/dom/document.rs, components/script/dom/domquad.rs, components/script/dom/vreyeparameters.rs, components/script/dom/cssgroupingrule.rs, components/script/dom/htmllegendelement.rs, components/script/dom/htmltableheadercellelement.rs, components/script/dom/element.rs, components/script/dom/cssrulelist.rs, components/script/dom/htmlparagraphelement.rs, components/script/dom/extendablemessageevent.rs, components/script/dom/vrdisplay.rs, components/script/dom/cssviewportrule.rs, components/script/docs/JS-Servos-only-GC.md, components/script/dom/htmlspanelement.rs, components/script/dom/webglobject.rs, components/script/dom/htmltemplateelement.rs, components/script/dom/htmllabelelement.rs, components/script/dom/htmlbaseelement.rs, components/script/dom/text.rs, components/script/dom/htmlstyleelement.rs, components/script/dom/bluetoothremotegattservice.rs, components/script/dom/url.rs, components/script/dom/htmltimeelement.rs, components/script/dom/htmlbrelement.rs, components/script/dom/dommatrixreadonly.rs, components/script/dom/dompointreadonly.rs, components/script/dom/stylesheetlist.rs, components/script/dom/performancetiming.rs, components/script/dom/webglshaderprecisionformat.rs, components/script/dom/storage.rs, components/script/dom/canvasrenderingcontext2d.rs, components/script/dom/cssstylerule.rs, components/script/dom/characterdata.rs, components/script/dom/webglactiveinfo.rs, components/script/dom/htmlfontelement.rs, components/script/dom/cssrule.rs, components/script/dom/htmlheadingelement.rs, components/script/dom/cssnamespacerule.rs, components/script/dom/serviceworkerglobalscope.rs, components/script/dom/htmlframesetelement.rs, components/script/dom/csskeyframerule.rs, components/script/dom/storageevent.rs, components/script/dom/htmlappletelement.rs, components/script/dom/htmltextareaelement.rs, components/script/dom/htmloptionscollection.rs, components/script/dom/mimetypearray.rs, components/script_plugins/lib.rs, components/script/dom/navigator.rs, components/script/dom/htmlhtmlelement.rs, components/script/dom/permissionstatus.rs, components/script/dom/screen.rs, components/script/dom/htmlquoteelement.rs, components/script/dom/htmlscriptelement.rs, components/script/dom/vrstageparameters.rs, components/script/dom/htmlaudioelement.rs, components/script/dom/documenttype.rs, components/script/dom/webgltexture.rs, components/script/dom/cssmediarule.rs, components/script/dom/vrframedata.rs, components/script/dom/testrunner.rs, components/script/dom/htmlunknownelement.rs, components/script/dom/window.rs, components/script/dom/htmltablerowelement.rs, components/script/dom/htmloptionelement.rs, components/script/dom/htmlobjectelement.rs, components/script/dom/filelist.rs, components/script/dom/forcetouchevent.rs, components/script/dom/comment.rs, components/script/dom/htmlvideoelement.rs, components/script/dom/htmlembedelement.rs, components/script/dom/htmloutputelement.rs, components/script/dom/mediaerror.rs, components/script/lib.rs, components/script/dom/validitystate.rs, components/script/dom/errorevent.rs, components/script/dom/dedicatedworkerglobalscope.rs, components/script/dom/nodelist.rs, components/script/dom/promisenativehandler.rs, components/script/dom/headers.rs, components/script/dom/domparser.rs, components/script/dom/bluetooth.rs, components/script/dom/cssconditionrule.rs, components/script/dom/bluetoothremotegattcharacteristic.rs, components/script/dom/htmlbodyelement.rs, components/script/dom/vrfieldofview.rs, components/script/dom/htmliframeelement.rs, components/script/dom/cssimportrule.rs, components/script/dom/filereadersync.rs, components/script/dom/permissions.rs, components/script/dom/testbindingiterable.rs, components/script/dom/medialist.rs, components/script/dom/xmlhttprequesteventtarget.rs, components/script/dom/transitionevent.rs, components/script/dom/htmlelement.rs, components/script/dom/htmlformelement.rs, components/script/dom/mediaquerylist.rs, components/script/dom/websocket.rs, components/script/dom/textencoder.rs, components/script/dom/htmltablecaptionelement.rs, components/script/dom/formdata.rs, components/script/dom/touchlist.rs
• @fitzgen: components/script/dom/request.rs, components/script/dom/workerlocation.rs, components/script/dom/xmldocument.rs, components/script/dom/svgelement.rs, components/script/dom/dompoint.rs, components/script/dom/webglframebuffer.rs, components/script/dom/crypto.rs, components/script/dom/client.rs, components/script/dom/focusevent.rs, components/script/dom/vrdisplaycapabilities.rs, components/script/dom/dissimilaroriginlocation.rs, components/script/dom/csskeyframesrule.rs, components/script/dom/htmlcanvaselement.rs, components/script/dom/blob.rs, components/script/dom/location.rs, components/script_plugins/jstraceable.rs, components/script/dom/htmldivelement.rs, components/script/dom/eventtarget.rs, components/script/dom/popstateevent.rs, components/script/dom/htmlfieldsetelement.rs, components/script/dom/htmlformcontrolscollection.rs, components/script/dom/workerglobalscope.rs, components/script/dom/pluginarray.rs, components/script/dom/imagedata.rs, components/script/dom/bluetoothpermissionresult.rs, components/script/dom/domstringmap.rs, components/script/dom/bindings/iterable.rs, components/script/dom/htmlpreelement.rs, components/script/dom/file.rs, components/script/dom/webglbuffer.rs, components/script/dom/htmlheadelement.rs, components/script/dom/svgsvgelement.rs, components/script/dom/htmlmapelement.rs, components/script/Cargo.toml, components/script/dom/keyboardevent.rs, components/script/dom/htmldetailselement.rs, components/script/dom/urlsearchparams.rs, components/script/dom/htmldialogelement.rs, components/script/dom/htmloptgroupelement.rs, components/script/dom/htmlimageelement.rs, components/script/dom/css.rs, components/script/dom/promise.rs, components/script/dom/worker.rs, components/script/dom/attr.rs, components/script/dom/htmlbuttonelement.rs, components/script/dom/svggraphicselement.rs, components/script/dom/webglrenderbuffer.rs, components/script/dom/globalscope.rs, components/script/dom/domrectreadonly.rs, components/script/dom/event.rs, components/script/dom/radionodelist.rs, components/script/dom/webglshader.rs, components/script/dom/htmldataelement.rs, components/script/dom/htmlanchorelement.rs, components/script/dom/node.rs, components/script/dom/workernavigator.rs, components/script/dom/serviceworkercontainer.rs, components/script/dom/canvasgradient.rs, components/script/dom/documentfragment.rs, components/script/dom/htmltableelement.rs, components/script/dom/htmltablesectionelement.rs, components/script/dom/progressevent.rs, components/script/dom/textdecoder.rs, components/script/dom/canvaspattern.rs, components/script/dom/htmldatalistelement.rs, components/script/dom/cssfontfacerule.rs, components/script/dom/dommatrix.rs, components/script/dom/bluetoothcharacteristicproperties.rs, components/script/dom/mouseevent.rs, components/script/dom/touchevent.rs, components/script/dom/range.rs, components/script/dom/testbindingproxy.rs, components/script/dom/htmlulistelement.rs, components/script/dom/htmlselectelement.rs, components/script/dom/pagetransitionevent.rs, components/script/dom/bluetoothuuid.rs, components/script/dom/htmldlistelement.rs, components/script/dom/processinginstruction.rs, components/script/dom/domrect.rs, components/script/dom/bluetoothdevice.rs, components/script/dom/htmlparamelement.rs, components/script/dom/htmldirectoryelement.rs, components/script/dom/htmllinkelement.rs, components/script/dom/performance.rs, components/script/dom/testbinding.rs, components/script/dom/cssstyledeclaration.rs, components/script/dom/webglrenderingcontext.rs, components/script/dom/browsingcontext.rs, components/script/dom/messageevent.rs, components/script/dom/webglcontextevent.rs, components/script/dom/xmlhttprequest.rs, components/script/dom/htmllielement.rs, components/script/dom/htmlmeterelement.rs, components/script/dom/serviceworker.rs, components/script/dom/bluetoothadvertisingevent.rs, components/script/dom/htmlmediaelement.rs, components/script/dom/customevent.rs, components/script/dom/htmltablecellelement.rs, components/script/dom/servoparser/mod.rs, components/script/dom/uievent.rs, components/script/dom/extendableevent.rs, components/script/dom/history.rs, components/script/dom/vrdisplayevent.rs, components/script/dom/testbindingpairiterable.rs, components/script/dom/htmlmodelement.rs, components/script/dom/stylesheet.rs, components/script/dom/namednodemap.rs, components/script/dom/mediaquerylistevent.rs, components/script/dom/domrectlist.rs, components/script/dom/touch.rs, components/script/dom/htmlinputelement.rs, components/script/dom/response.rs, components/script/dom/csssupportsrule.rs, components/script/dom/domimplementation.rs, components/script/dom/htmlareaelement.rs, components/script/dom/htmlsourceelement.rs, components/script/dom/htmltrackelement.rs, components/script/dom/htmlframeelement.rs, components/script/dom/serviceworkerregistration.rs, components/script/dom/domtokenlist.rs, components/script/dom/webglprogram.rs, components/script/dom/plugin.rs, components/script/dom/mimetype.rs, components/script/dom/htmlolistelement.rs, components/script/dom/xmlhttprequestupload.rs, components/script/dom/eventsource.rs, components/script/dom/closeevent.rs, components/script/dom/cssstylesheet.rs, components/script/dom/domexception.rs, components/script/dom/htmlhrelement.rs, components/script/dom/htmlprogresselement.rs, components/script/dom/htmltablecolelement.rs, components/script/dom/bluetoothremotegattdescriptor.rs, components/script/dom/htmlcollection.rs, components/script/dom/treewalker.rs, components/script/dom/nodeiterator.rs, components/script/dom/htmlmetaelement.rs, components/script/dom/vr.rs, components/script/dom/filereader.rs, components/script/dom/dissimilaroriginwindow.rs, components/script/dom/beforeunloadevent.rs, components/script/dom/htmltabledatacellelement.rs, components/script/dom/vrpose.rs, components/script/dom/webgluniformlocation.rs, components/script/dom/hashchangeevent.rs, components/script/dom/htmltitleelement.rs, components/script/dom/bluetoothremotegattserver.rs, components/script/dom/document.rs, components/script/dom/domquad.rs, components/script/dom/vreyeparameters.rs, components/script/dom/cssgroupingrule.rs, components/script/dom/htmllegendelement.rs, components/script/dom/htmltableheadercellelement.rs, components/script/dom/element.rs, components/script/dom/cssrulelist.rs, components/script/dom/htmlparagraphelement.rs, components/script/dom/extendablemessageevent.rs, components/script/dom/vrdisplay.rs, components/script/dom/cssviewportrule.rs, components/script/docs/JS-Servos-only-GC.md, components/script/dom/htmlspanelement.rs, components/script/dom/webglobject.rs, components/script/dom/htmltemplateelement.rs, components/script/dom/htmllabelelement.rs, components/script/dom/htmlbaseelement.rs, components/script/dom/text.rs, components/script/dom/htmlstyleelement.rs, components/script/dom/bluetoothremotegattservice.rs, components/script/dom/url.rs, components/script/dom/htmltimeelement.rs, components/script/dom/htmlbrelement.rs, components/script/dom/dommatrixreadonly.rs, components/script/dom/dompointreadonly.rs, components/script/dom/stylesheetlist.rs, components/script/dom/performancetiming.rs, components/script/dom/webglshaderprecisionformat.rs, components/script/dom/storage.rs, components/script/dom/canvasrenderingcontext2d.rs, components/script/dom/cssstylerule.rs, components/script/dom/characterdata.rs, components/script/dom/webglactiveinfo.rs, components/script/dom/htmlfontelement.rs, components/script/dom/cssrule.rs, components/script/dom/htmlheadingelement.rs, components/script/dom/cssnamespacerule.rs, components/script/dom/serviceworkerglobalscope.rs, components/script/dom/htmlframesetelement.rs, components/script/dom/csskeyframerule.rs, components/script/dom/storageevent.rs, components/script/dom/htmlappletelement.rs, components/script/dom/htmltextareaelement.rs, components/script/dom/htmloptionscollection.rs, components/script/dom/mimetypearray.rs, components/script_plugins/lib.rs, components/script/dom/navigator.rs, components/script/dom/htmlhtmlelement.rs, components/script/dom/permissionstatus.rs, components/script/dom/screen.rs, components/script/dom/htmlquoteelement.rs, components/script/dom/htmlscriptelement.rs, components/script/dom/vrstageparameters.rs, components/script/dom/htmlaudioelement.rs, components/script/dom/documenttype.rs, components/script/dom/webgltexture.rs, components/script/dom/cssmediarule.rs, components/script/dom/vrframedata.rs, components/script/dom/testrunner.rs, components/script/dom/htmlunknownelement.rs, components/script/dom/window.rs, components/script/dom/htmltablerowelement.rs, components/script/dom/htmloptionelement.rs, components/script/dom/htmlobjectelement.rs, components/script/dom/filelist.rs, components/script/dom/forcetouchevent.rs, components/script/dom/comment.rs, components/script/dom/htmlvideoelement.rs, components/script/dom/htmlembedelement.rs, components/script/dom/htmloutputelement.rs, components/script/dom/mediaerror.rs, components/script/lib.rs, components/script/dom/validitystate.rs, components/script/dom/errorevent.rs, components/script/dom/dedicatedworkerglobalscope.rs, components/script/dom/nodelist.rs, components/script/dom/promisenativehandler.rs, components/script/dom/headers.rs, components/script/dom/domparser.rs, components/script/dom/bluetooth.rs, components/script/dom/cssconditionrule.rs, components/script/dom/bluetoothremotegattcharacteristic.rs, components/script/dom/htmlbodyelement.rs, components/script/dom/vrfieldofview.rs, components/script/dom/htmliframeelement.rs, components/script/dom/cssimportrule.rs, components/script/dom/filereadersync.rs, components/script/dom/permissions.rs, components/script/dom/testbindingiterable.rs, components/script/dom/medialist.rs, components/script/dom/xmlhttprequesteventtarget.rs, components/script/dom/transitionevent.rs, components/script/dom/htmlelement.rs, components/script/dom/htmlformelement.rs, components/script/dom/mediaquerylist.rs, components/script/dom/websocket.rs, components/script/dom/textencoder.rs, components/script/dom/htmltablecaptionelement.rs, components/script/dom/formdata.rs, components/script/dom/touchlist.rs
• @emilio: components/script/dom/webglframebuffer.rs, components/script/dom/webglbuffer.rs, components/script/dom/webglrenderbuffer.rs, components/script/dom/webglshader.rs, components/script/dom/webglrenderingcontext.rs, components/script/dom/webglcontextevent.rs, components/script/dom/webglprogram.rs, components/script/dom/webgluniformlocation.rs, components/script/dom/webglobject.rs, components/script/dom/webglshaderprecisionformat.rs, components/script/dom/webglactiveinfo.rs, components/script/dom/webgltexture.rs

[nox]

@jdm Something tells me you are not going to like this...

[bors-servo]

☔ The latest upstream changes (presumably #15700) made this pull request unmergeable. Please resolve the merge conflicts.

[nox]

Oh yes of course, this is going to get bitrot all the time.

[jdm]

What's the error message if the import is missing?

[SimonSapin]

Can we use an absolute path like #[::dom_struct::dom_struct], so that no import is needed?

Or #[::dom_struct], with components/script/lib.rs changed like so:

extern crate dom_struct as dom_struct_crate;
pub use dom_struct_crate::dom_struct;

[nox]

What's the error message if the import is missing?

That `dom_struct` is undefined, and it suggests to import it with its path printed.

[nox]

Can we use an absolute path like `#[::dom_struct::dom_struct]`, so that no import is needed?

I guess yes but I would rather just keep the import.

[SimonSapin]

@bors-servo r+

[bors-servo]

📌 Commit 31e9d81 has been approved by SimonSapin

[bors-servo]

⌛ Testing commit 31e9d81 with merge a204c41...

[bors-servo]

☀️ Test successful - android, arm32, arm64, linux-dev, linux-rel-css, linux-rel-wpt, mac-dev-unit, mac-rel-css, mac-rel-wpt1, mac-rel-wpt2, windows-gnu-dev, windows-msvc-dev
Approved by: SimonSapin
Pushing a204c41 to master...