[clang] [llvm] [AMDGPU] Add per-kernel kernarg preload count (PR #211059)

[Aaron Ballman via cfe-commits]

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@@ -2525,6 +2525,13 @@ def AMDGPUNumVGPR : InheritableAttr {
   let Subjects = SubjectList<[Function], ErrorDiag, "kernel functions">;
 }
 
+def AMDGPUKernargPreloadCount : InheritableAttr {
+  let Spellings = [Clang<"amdgpu_kernarg_preload_count", 0>];
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AaronBallman wrote:

If the only reason is "other attributes did it", then I think there's follow-up work to fix some of this stuff up. (You don't have to do the follow-up work, but we should at least file an issue so someone knows the work should happen.) We already have to support the semantics in C because of the GNU spelling, so there's no compelling reason not to support the `[[]]` syntax. As for target specific attributes, we have a de facto policy that ignored attributes get diagnosed as being ignored.

As for this PR, it's fine to follow the existing pattern.

https://github.com/llvm/llvm-project/pull/211059