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

[Alexander Yermolovich via llvm-commits]

ayermolo wrote:

> > Per my understanding, these two mutex are required to protect any read/write to DieArray field? If so, there seem to be many more accesses of this field not protected?
> 
> They're there for protecting the allocation+population, or destruction of the DieArrays, not generally reading/writing those fields. There needs to be two (for just the first CUDie, and then the whole array) as populating the first can trigger a request to populate the rest.

What is the code path for that?

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