[compiler-rt] Add API to temporalily disable usage of ASAN's fake stack (PR #160135)

[Vitaly Buka via llvm-commits]

vitalybuka wrote:

I thought StartSwitchFiber was added for that

I am not sure I understand what is special with MADV_DONTDUMP
Can you add a test which essentially reproduces the issue?
You don't need to remove the existing test.

https://github.com/llvm/llvm-project/pull/160135