[compiler-rt] move tsan's Android __get_tls() to sanitizer_common

Summary:
TSan's Android `__get_tls()` and `TLS_SLOT_TSAN` can be used by other sanitizers as well (see D32649), this change moves them to sanitizer_common.
I picked sanitizer_linux.h as their new home.
In the process, add the 32-bit versions for ARM, i386 & MIPS.

Can the address of `__get_tls()[TLS_SLOT_TSAN]` change in between the calls?
I am not sure if there is a need to repeat the construct as opposed to using a variable. So I left things as they were.

Testing on my side was restricted to a successful cross-compilation.

Reviewers: dvyukov, kubamracek

Reviewed By: dvyukov

Subscribers: aemerson, rengolin, srhines, dberris, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D32705

llvm-svn: 301926