[clang] [clang] Function type attribute to prevent CFI instrumentation (PR #135836)

[via cfe-commits]

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@@ -1988,7 +1988,7 @@ class alignas(TypeAlignment) Type : public ExtQualsTypeCommonBase {
     /// Extra information which affects how the function is called, like
     /// regparm and the calling convention.
     LLVM_PREFERRED_TYPE(CallingConv)
-    unsigned ExtInfo : 14;
+    unsigned ExtInfo : 15;
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PiJoules wrote:

Hmm. I suppose I could move it to `ExtProtoInfo` in `FunctionPrototype` and forgo attaching this to non function prototypes. I would hope adding it there instead doesn't add extra overhead since it aleady has a couple of members already and we wouldn't need to bring in another trailing object like what's needed for `FunctionTypeExtraBitfields`.

https://github.com/llvm/llvm-project/pull/135836