[clang] [HLSL] Implement output parameter (PR #101083)

[Chris B via cfe-commits]

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@@ -4613,14 +4613,13 @@ def HLSLGroupSharedAddressSpace : TypeAttr {
   let Documentation = [HLSLGroupSharedAddressSpaceDocs];
 }
 
-def HLSLParamModifier : TypeAttr {
+def HLSLParamModifier : ParameterABIAttr {
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llvm-beanz wrote:

DXC currently parses but ignores the `uniform` keyword. We have an issue to just officially remove it from the language in 202x since it doesn't do anything, so my plan is to not implement it in Clang at all (https://github.com/microsoft/hlsl-specs/issues/135)

https://github.com/llvm/llvm-project/pull/101083