[clang] [clang] Implement function pointer type discrimination (PR #96992)

[Akira Hatanaka via cfe-commits]

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@@ -470,6 +470,9 @@ ENUM_LANGOPT(StrictFlexArraysLevel, StrictFlexArraysLevelKind, 2,
 
 COMPATIBLE_VALUE_LANGOPT(MaxTokens, 32, 0, "Max number of tokens per TU or 0")
 
+BENIGN_LANGOPT(FunctionPointerTypeDiscrimination, 1, 0,
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ahatanak wrote:

I moved the langopt closer to other pointer auth langopts. I think we can convert other pointer auth langopts to `BENIGN_LANGOPT` or `BENIGN_ENUM_LANGOPT` as they probably don't affect the construction of the AST.

https://github.com/llvm/llvm-project/pull/96992