Make the sym_diff utilities more useful.

In particular when working with static libraries and libstdc++.

llvm-svn: 353772
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 1eb19e52774a4cea757b9214fc3c8e8e6318ef64
3 files changed