The way libunwind handles local unwinds is different from remote unwinds,
so create a new map object to handle the differences.
Add new test to verify the map data is being generated correctly.
Add new tests to check for leaks.
Refactor the BACK_LOGW code into a single header file.
Change-Id: I01f3cbfc4b927646174ea1b614fa25d23b9b3427
