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

[David Spickett via llvm-commits]

DavidSpickett wrote:

@kazutakahirata , I think this would reproduce by doing `ninja check-mlir` on any AArch64 machine. If you do not have access to one, @omjavaid can test your fixes for you.

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