[llvm] [ARM] Mark function calls as possibly changing FPSCR (PR #160699)

[Erik Enikeev via llvm-commits]

Varnike wrote:

As @statham-arm suggested, it would be more correct to use FPSCR_RM instead of FPSCR. However this leads to the fact that this patch becomes dependent on #160698, so it won't be possible to commit it for now.

https://github.com/llvm/llvm-project/pull/160699