header-abi-dumper: dumps abi exported by source files for Vndk.
header-abi-linker: links abi dumps produced by header-abi-dumper.
header-abi-diff: compares linked dumps.
Test: mm -j64 showcommands > make_log in bionic/libc.
This produced linked dumps in out/soong/.intermediates.
Copied these dumps to
prebuilts/abi-dumps/ndk/current/arm64/source-based/.
Changed the abi and re-ran mm -j64 showcommands > make_log
confirmed that the build reported compatibility breakge without
actually failing (advisory mode).
Change-Id: Iccad6908fe68a80f47230751671d156893b96ead
