[sanitizer] Move the errno/ENOMEM allocator checks logic to separate .cc

Summary:
This is a new attempt at D38706, which had 2 issues.

The first one was that it broke TSan, because `sanitizer_errno.h` was not
directly included in `tsan_mman.cc`. This fixes the include.

The second one was that it broke the nolibc build, because `__errno_location`
couldn't be found. This adds the new .cc to the libcdep list instead of the
base one.

Reviewers: alekseyshl

Reviewed By: alekseyshl

Subscribers: kubamracek, mgorny, llvm-commits

Differential Revision: https://reviews.llvm.org/D38743

llvm-svn: 315509