[llvm] [AArch64] ConditionOptimizer: replace per-block DenseMap with ScopedHashTable traversal (PR #196746)

[Hussam Alhassan via llvm-commits]

hussam-alhassan wrote:

Compiling `clang/lib/` and `llvm/lib/` to AArch64 sees an increase in NumConditionsAdjusted from 210 to 303, about 44%+

https://github.com/llvm/llvm-project/pull/196746