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

[Cassandra Beckley via llvm-commits]

================
@@ -4005,6 +4017,38 @@ bool SPIRVInstructionSelector::loadVec3BuiltinInputID(
   return Result && MIB.constrainAllUses(TII, TRI, RBI);
 }
 
+// Generate the instructions to load 32-bit integer builtin input IDs/Indices.
+// Like LocalInvocationIndex
+bool SPIRVInstructionSelector::loadBuiltinInputID(
+    SPIRV::BuiltIn::BuiltIn BuiltInValue, Register ResVReg,
+    const SPIRVType *ResType, MachineInstr &I) const {
----------------
cassiebeckley wrote:

Good idea, done.

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