[clang] [llvm] [clang] Add spir_kernel attribute (PR #137882)

[Erich Keane via cfe-commits]

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@@ -1504,6 +1506,12 @@ def NVPTXKernel : InheritableAttr, TargetSpecificAttr<TargetNVPTX> {
   let Documentation = [Undocumented];
 }
 
+def SPIRKernel : InheritableAttr, TargetSpecificAttr<TargetAnySPIR> {
+  let Spellings = [Clang<"spir_kernel">];
+  let Subjects = SubjectList<[Function]>;
+  let Documentation = [Undocumented];
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erichkeane wrote:

Why is this non-documented?  WE very much don't approve/accept new undocumented attributes without good reason.

https://github.com/llvm/llvm-project/pull/137882