naga: Enforce @must_use for built-in functions

CHANGELOG.md

@@ -207,6 +207,7 @@ By @cwfitzgerald in [#8609](https://github.com/gfx-rs/wgpu/pull/8609).
 - Prevent UB with invalid ray query calls on spirv. By @Vecvec in [#8390](https://github.com/gfx-rs/wgpu/pull/8390).
 - Update the set of binding_array capabilities. In most cases, they are set automatically from `wgpu` features, and this change should not be user-visible. By @andyleiserson in [#8671](https://github.com/gfx-rs/wgpu/pull/8671).
 - Naga now accepts the `var<function>` syntax for declaring local variables. By @andyleiserson in [#8710](https://github.com/gfx-rs/wgpu/pull/8710).
+- Naga now enforces the `@must_use` attribute on WGSL built-in functions, when applicable. You can waive the error with a phony assignment, e.g., `_ = subgroupElect()`. By @andyleiserson in [#8713](https://github.com/gfx-rs/wgpu/pull/8713).
 
 ### Bug Fixes
 

cts_runner/test.lst

@@ -176,7 +176,25 @@ webgpu:shader,execution,flow_control,return:*
 // Fails on Metal in CI only, not when running locally.
 fails-if(metal) webgpu:shader,execution,robust_access_vertex:vertex_buffer_access:indexed=true;indirect=false;drawCallTestParameter="baseVertex";type="float32x4";additionalBuffers=4;partialLastNumber=false;offsetVertexBuffer=true
 webgpu:shader,validation,expression,call,builtin,all:arguments:test="ptr_deref"
-webgpu:shader,validation,expression,call,builtin,max:values:*
+webgpu:shader,validation,expression,call,builtin,arrayLength:*
+webgpu:shader,validation,expression,call,builtin,barriers:*
+webgpu:shader,validation,expression,call,builtin,cos:*
+webgpu:shader,validation,expression,call,builtin,floor:*
+webgpu:shader,validation,expression,call,builtin,fract:*
+webgpu:shader,validation,expression,call,builtin,max:*
+webgpu:shader,validation,expression,call,builtin,min:*
+webgpu:shader,validation,expression,call,builtin,radians:*
+webgpu:shader,validation,expression,call,builtin,sign:*
+webgpu:shader,validation,expression,call,builtin,sin:*
+webgpu:shader,validation,expression,call,builtin,step:*
+webgpu:shader,validation,expression,call,builtin,tan:*
+webgpu:shader,validation,expression,call,builtin,tanh:*
+webgpu:shader,validation,expression,call,builtin,textureNumLayers:*
+webgpu:shader,validation,expression,call,builtin,textureNumLevels:*
+webgpu:shader,validation,expression,call,builtin,textureNumSamples:*
+webgpu:shader,validation,expression,call,builtin,textureStore:*
+webgpu:shader,validation,expression,call,builtin,trunc:*
+webgpu:shader,validation,expression,call,builtin,workgroupUniformLoad:*
 webgpu:shader,validation,statement,statement_behavior:invalid_statements:body="break"
 webgpu:shader,validation,statement,statement_behavior:invalid_statements:body="break_if"
 webgpu:shader,validation,statement,statement_behavior:invalid_statements:body="continue"