[compiler-rt] [scudo] Add primary option to enable/disable cache blocks. (PR #129794)

[Jordan R AW via llvm-commits]

https://github.com/ajordanr-google commented:

Conceptually, this all makes sense to me.

The exact algorithmic details of the Batch Allocate/Deallocate are not super clear to me, but I do understand why it's useful.

The motivation of the whole PR has not quite hit me yet. I assume it's for lower memory usage during multi-threaded execution, but it's not clear from the option that this is the intent.

Otherwise my remaining comments are nits/LLVM style guide things.

https://github.com/llvm/llvm-project/pull/129794