[llvm] [SPIR-V] Add support for HLSL SV_GroupIndex (PR #130670)

[Nathan Gauër via llvm-commits]

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@@ -0,0 +1,32 @@
+; RUN: llc -O0 -verify-machineinstrs -mtriple=spirv-vulkan-unknown %s -o - | FileCheck %s
+; RUN: %if spirv-tools %{ llc -O0 -mtriple=spirv-vulkan-unknown %s -o - -filetype=obj | spirv-val %}
+
+; CHECK-DAG:        %[[#int:]] = OpTypeInt 32 0
+; CHECK-DAG:        %[[#ptr_Input_int:]] = OpTypePointer Input %[[#int]]
+; CHECK-DAG:        %[[#LocalInvocationIndex:]] = OpVariable %[[#ptr_Input_int]] Input
+
+; CHECK-DAG:        OpEntryPoint GLCompute {{.*}} %[[#LocalInvocationIndex]]
+; CHECK-DAG:        OpName %[[#LocalInvocationIndex]] "__spirv_BuiltInLocalInvocationIndex"
+; CHECK-DAG:        OpDecorate %[[#LocalInvocationIndex]] LinkageAttributes "__spirv_BuiltInLocalInvocationIndex" Import
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Keenuts wrote:

I'd say either remove this check, and create an todo/issue to track this cleanup, or change what's being generated.
But IMO adding a `CHECK` line for this would mean `this is the desired behavior` 

https://github.com/llvm/llvm-project/pull/130670