[llvm] Reduce llvm-gsymutil memory usage (PR #91023)

[David Blaikie via llvm-commits]

dwblaikie wrote:

Is it worth having 3 separate mutexes? One answer would be to go fully coarse grained - just have 1 that covers the whole array. Does that have noticably worse performance for your use case?

The other option would be 2 - you have one covering the first element of the array, and another covering the rest - I guess then you have problems when reallocating the array, though?

https://github.com/llvm/llvm-project/pull/91023