[compiler-rt] [asan] Switch initialization to "double-checked locking" (PR #74387)

[Dmitry Vyukov via llvm-commits]

https://github.com/dvyukov approved this pull request.

I don't have any objections.
There may be some subtle implications, or maybe not. I guess it's impossible to understand w/o merging this.
The increased critical section may lead to deadlocks on recursion, or not.

https://github.com/llvm/llvm-project/pull/74387