[clang] [HLSL][clang] Move hlsl_wave_get_lane_index to EmitHLSLBuiltinExpr (PR #87131)

[Marc Auberer via cfe-commits]

marcauberer wrote:

@farzonl All three tests pass 👍🏽 

```sh
$ ./bin/llvm-lit ../llvm/test/CodeGen/SPIRV/hlsl-intrinsics/WaveGetLaneIndex.ll ../llvm/test/CodeGen/SPIRV/scfg-add-pre-headers.ll ../llvm/test/CodeGen/SPIRV/transcoding/spirv-private-array-initialization.ll
-- Testing: 3 tests, 3 workers --
PASS: LLVM :: CodeGen/SPIRV/scfg-add-pre-headers.ll (1 of 3)
PASS: LLVM :: CodeGen/SPIRV/transcoding/spirv-private-array-initialization.ll (2 of 3)
PASS: LLVM :: CodeGen/SPIRV/hlsl-intrinsics/WaveGetLaneIndex.ll (3 of 3)

Testing Time: 0.04s

Total Discovered Tests: 3
  Passed: 3 (100.00%)
```

https://github.com/llvm/llvm-project/pull/87131