[clang] [PAuth] Use different discriminators for __int128_t / __uint128_t / _BitInt(n) (PR #140276)

[Oliver Hunt via cfe-commits]

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@@ -1883,6 +1883,9 @@ void Clang::AddAArch64TargetArgs(const ArgList &Args,
   Args.addOptInFlag(
       CmdArgs, options::OPT_fptrauth_function_pointer_type_discrimination,
       options::OPT_fno_ptrauth_function_pointer_type_discrimination);
+  Args.addOptInFlag(
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ojhunt wrote:

there's apple kernel flags in this function, but it looks like darwin args are actually set up in `Toolchains/Darwin.cpp` - can the apple invocation paths hit this? if not I think it's worth just having this as an opt out rather than an opt in. We might be constrained by ABI, but I don't think you have any reason to restrict this.

My request for a cli/langopt was so that we can stick with our existing ABI if need be, not because I thought you couldn't do this :D

https://github.com/llvm/llvm-project/pull/140276