simpleperf: report: add an option to specify symbol searching directory

Allow user to specify a directory containing symbols instead of needing
a directory structure matching the dso path. This is useful for
specifying symbols for dynamic libraries included in APKs such as
libmonochrome_x64.so for chromium.

Bug: none
Test: `simpleperf report --lib DIR_WITH_SYMBOLS ...`
      `simpleperf_unit_test`
Change-Id: Ifb1bef62899cfbe25594d1de4cf2f17574706926
2 files changed