Auto merge of #15911 - servo:rustup_, r=emilio

Update to rustc 1.17.0-nightly (8c72b7651 2017-03-11)

This fixes the DOM node size regression introduced by a previous Rust update: #15704

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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [ ] These changes fix #__ (github issue number if applicable).

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rust-commit-hash

@@ -1 +1 @@
-413a975e31584d1e22d158a70c6d3073b991a618
+8c72b7651f231f589bc81d78fb9602d5a0899213

tests/unit/script/size_of.rs

@@ -29,14 +29,14 @@ macro_rules! sizeof_checker (
 );
 
 // Update the sizes here
-sizeof_checker!(size_event_target, EventTarget, 48);
-sizeof_checker!(size_node, Node, 160);
-sizeof_checker!(size_element, Element, 320);
-sizeof_checker!(size_htmlelement, HTMLElement, 336);
-sizeof_checker!(size_div, HTMLDivElement, 336);
-sizeof_checker!(size_span, HTMLSpanElement, 336);
-sizeof_checker!(size_text, Text, 192);
-sizeof_checker!(size_characterdata, CharacterData, 192);
+sizeof_checker!(size_event_target, EventTarget, 40);
+sizeof_checker!(size_node, Node, 152);
+sizeof_checker!(size_element, Element, 312);
+sizeof_checker!(size_htmlelement, HTMLElement, 328);
+sizeof_checker!(size_div, HTMLDivElement, 328);
+sizeof_checker!(size_span, HTMLSpanElement, 328);
+sizeof_checker!(size_text, Text, 184);
+sizeof_checker!(size_characterdata, CharacterData, 184);
 sizeof_checker!(size_servothreadsafelayoutnode, ServoThreadSafeLayoutNode, 16);
 
 // We use these types in the parallel traversal. They should stay pointer-sized.