simpleperf: Add a python class to wrap addr2line.

addr2line doesn't generate line info for instructions without a
matching statement. So build a class called Addr2NearestLine
to overcome this.
Also add test for it.

It is a preparation to show annotated source code in html interface.

Bug: http://b/66914187
Test: run test.py TestTools.

Change-Id: I70f8d99ffc7c25bca17a01469e21f16a7bdd04c5
7 files changed