[WebGPU] explicit layouts should be validated for compatibility with the shader

[mwyrzykowski]

646adca

[WebGPU] explicit layouts should be validated for compatibility with the shader
https://bugs.webkit.org/show_bug.cgi?id=282710
rdar://138847403

Reviewed by Dan Glastonbury.

There is a bug in our validation code that checks the compatibility between the
variables used by the shader and the bind group provided via the API, and it happens
in two steps:
- first, we start by traversing the API-provided bind group we check if the shader
  contains a variable for that group/binding pair. Here we incorrectly check against
  all the variables in the shader, but we should only consider the variables that
  are actually used, since it's valid to have multiple variables with the same
  binding, so long as they are not used by the same entry point.
- the second part of the code is actually correct, where we only validate the used
  variables against the bind group. However, since we incorrectly selected an unused
  variable to be serialized in the previous step, that variable is never, allowing
  a type mismatch between the generated shader and the bind group.

* LayoutTests/fast/webgpu/nocrash/fuzz-282710-expected.txt: Added.
* LayoutTests/fast/webgpu/nocrash/fuzz-282710.html: Added.
* Source/WebGPU/WGSL/GlobalVariableRewriter.cpp:
(WGSL::RewriteGlobalVariables::insertStructs):

Canonical link: https://commits.webkit.org/286432@main

8ba74e8

Misc	iOS, visionOS, tvOS & watchOS	macOS	Linux	Windows
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	⏳ 🛠 ios-sim	✅ 🛠 mac-AS-debug	🧪 wpe-wk2	🧪 win-tests
✅ 🧪 webkitperl	⏳ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe
	⏳ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	🛠 wpe-cairo
	⏳ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🛠 gtk
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[webkit-early-warning-system]

EWS run on previous version of this PR (hash 4f9613a)

Misc	iOS, visionOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 win
	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2	✅ 🧪 win-tests
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe
	✅ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	✅ 🛠 wpe-cairo
	❌ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🛠 gtk
	✅ 🛠 vision	✅ 🧪 mac-AS-debug-wk2	✅ 🧪 gtk-wk2
	✅ 🛠 vision-sim	✅ 🧪 mac-wk2-stress	✅ 🧪 api-gtk
	✅ 🧪 vision-wk2	✅ 🧪 mac-intel-wk2
	✅ 🛠 tv
	✅ 🛠 tv-sim
	✅ 🛠 watch
	✅ 🛠 watch-sim

[djg]

[webkit-early-warning-system]

EWS run on current version of this PR (hash 8ba74e8)

Misc	iOS, visionOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	⏳ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 win
	⏳ 🛠 ios-sim	✅ 🛠 mac-AS-debug	🧪 wpe-wk2	🧪 win-tests
✅ 🧪 webkitperl	⏳ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe
	⏳ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	🛠 wpe-cairo
	⏳ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🛠 gtk
	✅ 🛠 vision	✅ 🧪 mac-AS-debug-wk2	🧪 gtk-wk2
	✅ 🛠 vision-sim	✅ 🧪 mac-wk2-stress	✅ 🧪 api-gtk
✅ 🛠 🧪 merge	✅ 🧪 vision-wk2	✅ 🧪 mac-intel-wk2
	✅ 🛠 tv
	✅ 🛠 tv-sim
	✅ 🛠 watch
	✅ 🛠 watch-sim

[webkit-commit-queue]

Committed 286432@main (646adca): https://commits.webkit.org/286432@main

Reviewed commits have been landed. Closing PR #36284 and removing active labels.