[clang] [SPIR-V] Add hlsl_private address space for HLSL/SPIR-V (PR #122103)

[Matt Arsenault via cfe-commits]

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@@ -58,6 +58,7 @@ enum class LangAS : unsigned {
 
   // HLSL specific address spaces.
   hlsl_groupshared,
+  hlsl_private,
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arsenm wrote:

> only SPIR-V will be using this for now

That's not really how languages work. It's a property of the language and exists independently of what any codegen is doing with it. As it is it sounds like you're jamming some knob you want for codegen through here that isn't part of the language.

This needs reference to some HLSL spec describing the address space without any mention of SPIRV.

https://github.com/llvm/llvm-project/pull/122103