[compiler-rt] [scudo] Support no-preserve-all-regions mode (PR #85149)

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ChiaHungDuan wrote:

> Is there good coverage of the no preserve case?
> 
> I know you changed the config in primary_test.cpp, but I'm not sure how much coverage that will get.

The only difference between TestConfig2 and TestConfig3 is whether `MaySupportMemoryTagging` is set. Therefore, it shares the same test coverage as before when memory tagging is disabled. It's unfortunate that we have so subtle differences between those test configs and I think we need to review the test configs and at least rename/add comments to them. 

https://github.com/llvm/llvm-project/pull/85149