[clang] [clang] Add noipa attribute (PR #207502)

[via cfe-commits]

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@@ -2420,6 +2420,13 @@ def NoOutline : DeclOrStmtAttr {
   let SimpleHandler = true;
 }
 
+def NoIPA : InheritableAttr {
+  let Spellings = [GCC<"noipa">];
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Disservin wrote:

i wasn't particular sure which spellings are expected for this, so some feedback would also be great

https://github.com/llvm/llvm-project/pull/207502