[llvm] Add FPMR register and update dependencies of FP8 instructions (PR #102910)

[Paul Walker via llvm-commits]

================
@@ -10137,7 +10137,7 @@ let Predicates = [HasD128] in {
 // 2023 Architecture Extensions:
 //===----------------------------===//
 
-let Predicates = [HasFP8] in {
+let Uses=[FPMR, FPCR], Predicates = [HasFP8] in {
----------------
paulwalker-arm wrote:

Please can you follow the existing style re spaces. So in this case it would be 
```
Uses = [FPMR, FPCR]
```

https://github.com/llvm/llvm-project/pull/102910