[clang] [TBAA] Emit int TBAA metadata on FP math libcall expf (PR #96025)

[Eli Friedman via cfe-commits]

https://github.com/efriedma-quic commented:

>> How does this interact with StrictFP?

> I don't think it related to StrictFP, because we only care whether the global variable errno is modified? which may bring in alias to other global variable. As now the type of errno is int, so we record that for related function.

In strictfp mode, expf() can also modify the floating-point status bits... which count as "memory".  So we need to make sure we treat reads and writes to the status bits as aliasing.

https://github.com/llvm/llvm-project/pull/96025