simpleperf: add stuff in report_lib_interface.

It's a preparation to annotate binaries, containing following
changes:
1. Export build_id for binaries.
2. Export function virtual addresses.
3. Add unit tests in simpleperf_report_lib.py.

Bug: http://b/32834638
Test: simpleperf_unit_test.
Test: run `python simpleperf_report_lib.py`.
Change-Id: Ieed40935ff9ede44bf823ba9c88ad87806ffac0a
5 files changed