[PATCH] Add symbol checking script to libc++ to detect ABI changes.

[Eric Fiselier]

That can definitively be supported. Initial investigation shows that llvm-nm has a different POSIX output format compared to nm on linux and mac, but all of the same information is there.
llvm-nm also outputs about 1200 more symbols that in any of my current baselines.  I'll get it working tonight.

Thanks for looking at this.

http://reviews.llvm.org/D4946