[clang] [Clang][HLSL] Start emitting structured GEP instruction (PR #177332)

[Deric C. via cfe-commits]

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@@ -248,6 +248,7 @@ LANGOPT(HLSLStrictAvailability, 1, 0, NotCompatible,
         "Strict availability diagnostic mode for HLSL built-in functions.")
 LANGOPT(HLSLSpvUseUnknownImageFormat, 1, 0, NotCompatible, "For storage images and texel buffers, sets the default format to 'Unknown' when not specified via the `vk::image_format` attribute. If this option is not used, the format is inferred from the resource's data type.")
 LANGOPT(HLSLSpvEnableMaximalReconvergence, 1, 0, NotCompatible, "Enables the MaximallyReconvergesKHR execution mode for this module. This ensures that control flow reconverges at well-defined merge points as defined by the Vulkan spec.")
+LANGOPT(EmitStructuredGEP, 1, 0, NotCompatible, "Emit structured_gep instructions instead of GEP")
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Icohedron wrote:

nit: perhaps the description of the LANGOPT should match more closely with the help text of the command line flag.
```suggestion
LANGOPT(EmitStructuredGEP, 1, 0, NotCompatible, "Emit structured GEP intrinsics instead of GEP instructions")
```

https://github.com/llvm/llvm-project/pull/177332