[clang-tidy] Fix check for Abseil internal namespace access

This change makes following modifications:
  * If reference originated from macro expansion, we report location inside of
    the macro instead of location where macro is referenced.
  * If for any reason deduced location is not correct we silently ignore it.

Patch by Gennadiy Rozental (rogeeff@google.com)
Reviewed as https://reviews.llvm.org/D72484