Revert 502f0cc0e38 "[GWP-ASan] Split the unwinder into segv/non-segv."

It was causing tests to fail in -DCOMPILER_RT_BUILD_BUILTINS=OFF builds:

   GwpAsan-Unittest :: ./GwpAsan-x86_64-Test/BacktraceGuardedPoolAllocator.DoubleFree
   GwpAsan-Unittest :: ./GwpAsan-x86_64-Test/BacktraceGuardedPoolAllocator.UseAfterFree

see comment on the code review.

> Summary:
> Splits the unwinder into a non-segv (for allocation/deallocation traces) and a
> segv unwinder. This ensures that implementations can select an accurate, slower
> unwinder in the segv handler (if they choose to use the GWP-ASan provided one).
> This is important as fast frame-pointer unwinders (like the sanitizer unwinder)
> don't like unwinding through signal handlers.
>
> Reviewers: morehouse, cryptoad
>
> Reviewed By: morehouse, cryptoad
>
> Subscribers: cryptoad, mgorny, eugenis, pcc, #sanitizers
>
> Tags: #sanitizers
>
> Differential Revision: https://reviews.llvm.org/D83994

This reverts commit 502f0cc0e3889229e923e187f38dda91324ae139.

GitOrigin-RevId: ab6263c9258ccd0e3c9cb4f675979f22cfba6131
Change-Id: I11af83299962daf40ddbc0982435c87994149a26
5 files changed