[clang] [clang][ARM64EC] Add support for hybrid_patchable attribute. (PR #99478)

[Jacek Caban via cfe-commits]

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@@ -4027,6 +4030,12 @@ def SelectAny : InheritableAttr {
   let SimpleHandler = 1;
 }
 
+def HybridPatchable : DeclOrTypeAttr, TargetSpecificAttr<TargetArm64EC> {
+  let Spellings = [Declspec<"hybrid_patchable">, GCC<"hybrid_patchable">];
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cjacek wrote:

Yes, I was thinking mostly about `__attribute__((hybrid_patchable))` as it's the form that mingw will mostly likely want to use, so I meant `GNU`. `Clang` sounds good to me if proffered, I changed that and added a test for it.

https://github.com/llvm/llvm-project/pull/99478