[llvm] [ExecutionEngine] Avoid repeated hash lookups (NFC) (PR #132587)

[David Spickett via llvm-commits]

DavidSpickett wrote:

A normal AArch64 build: https://lab.llvm.org/buildbot/#/builders/84/builds/1436
An AArch64 with SVE build: https://lab.llvm.org/buildbot/#/builders/17/builds/6730

Both got hit which means this isn't SVE specific. Lots of MLIR failures, that use `mlir-runner`, which uses LLVM's ExecutionEngine. Which makes sense given that there are changes in the function `resolveAArch64Branch`.

And explains why no other platform had this problem.

https://github.com/llvm/llvm-project/pull/132587