[NFC][Sanitizer] Pull up GetStackTrace into sanitizer_common

We already independently declare GetStackTrace in all (except TSan)
sanitizer runtime headers. Lets move it to sanitizer_stacktrace.h to
have one canonical way to fill in a BufferedStackFrame. Also enables us
to use it in sanitizer_common itself.

This patch defines GetStackTrace for TSan and moves the function from
ubsan_diag.cc to ubsan_diag_standalone.cc to avoid duplicate symbols
for the UBSan-ASan runtime.

Other than that this patch just moves the code out of headers and into
the correct namespace.

Reviewers: vitalybuka

Differential Revision: https://reviews.llvm.org/D58651

llvm-svn: 355039