[clang] [llvm] [Clang][AArch64] Implement widening FMMLA intrinsics (PR #165282)

[via llvm-commits]

CarolineConcatto wrote:

Another thin @efriedma-quic 
I saw the comments about creating an intrinsic for each rouding mode, but we believe that is not enough for the FP8 instruction. Because it is not setting only the routing mode that FPMR set,  but also scales, overflow and saturations. We've consider that solution as well, but I think that main reason was that this would be more complex for the user than just having one intrinsic for each instruction and  setting fpmr for what was desired
 

https://github.com/llvm/llvm-project/pull/165282