[llvm] [ARM] Add mayRaiseFPException to appropriate instructions and mark all instructions that read/write fpscr rounding bits as doing so (PR #160698)

[Erik Enikeev via llvm-commits]

Varnike wrote:

As far as I've seen from their description, these instructions don't use rounding mode bits and don't raise fp exceptions. For this reason, I didn't change them in the commit.

https://github.com/llvm/llvm-project/pull/160698