1) We do not involve the build system to create test reference dumps. Symbols
in tests, are faked through version scripts to avoid checking in prebuilt .so
test files.
2) Also add a script to create reference abi dumps.
3) Fix a comment in ast_processing.cpp
Test: Run tests/test.py, all tests run and pass on generic arm64, mips64
and x86_64 builds.
Change-Id: Id3a420c1ae093a05a79da4c29e85071f28d714d1