[llvm] llvm-reduce: Avoid double map lookup (PR #133447)

[Kazu Hirata via llvm-commits]

kazutakahirata wrote:

> This would change behavior if there are recursive MDNodes, but I'm not sure those are a thing.

I haven't seen one, but I'm not sure either.  That said, this is just `llvm-reduce`.  The external interestingness test guarantees the interestingness, so the worse case is `llvm-reduce` producing a suboptimal result or crashing.


https://github.com/llvm/llvm-project/pull/133447