[WHLSL] Call arguments should be copied as soon as they are evaluated

[litherum]

Migrated from https://bugs.webkit.org/show_bug.cgi?id=189360:

At 2018-09-06T17:52:08Z, tdenney@apple.com wrote:
There is an observable bug in the interpreter whereby the shallow copy of values only occurred after all arguments to a call had been evaluated.

[litherum]

At 2018-09-06T18:00:18Z, tdenney@apple.com wrote:
Created attachment 349045
Patch

[litherum]

At 2018-09-06T18:12:27Z, mmaxfield@apple.com wrote:
Comment on attachment 349045
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=349045&action=review

Tools/WebGPUShadingLanguageRI/Evaluator.js:325

•    let result = EBuffer.allowAllocation(() => node.func.implementation(callArguments, node));
  

I'm confused. Where do the thunks get evaluated? I expected this patch to move code around, but instead it appears to be deleting code?

[litherum]

At 2018-09-06T20:11:01Z, mmaxfield@apple.com wrote:
Comment on attachment 349045
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=349045&action=review

Tools/WebGPUShadingLanguageRI/Evaluator.js:325

•    let result = EBuffer.allowAllocation(() => node.func.implementation(callArguments, node));
  

I'm confused. Where do the thunks get evaluated? I expected this patch to move code around, but instead it appears to be deleting code?

Got it. Looks good.

[litherum]

At 2018-09-06T20:36:49Z, commit-queue@webkit.org wrote:
Comment on attachment 349045
Patch

Clearing flags on attachment: 349045

Committed r235753: https://trac.webkit.org/changeset/235753

[litherum]

At 2018-09-06T20:36:50Z, commit-queue@webkit.org wrote:
All reviewed patches have been landed. Closing bug.

[litherum]

At 2018-09-06T20:40:26Z, webkit-bug-importer@group.apple.com wrote:
rdar://problem/44194725