[clang] [PAC] Implement function pointer re-signing (PR #98847)

[Daniil Kovalev via cfe-commits]

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kovdan01 wrote:

Could you please clarify what tests should go to ptrauth.c? The test name is very generic, and we have more than 10 tests with clang/test/CodeGen/ptrauth*.c names. Maybe this should be renamed to smth more specific?

https://github.com/llvm/llvm-project/pull/98847