[PATCH] Fixup PPC symbol versioning for libgcc symbols

[Roland McGrath]

The SHLIB_COMPAT tests are in there so it looks like it will be ok.  The
thing to look for is that the library built with --enable-oldest-abi=2.3
does not contain the compatibility symbols that this patch adds.  I don't
have a clean copy of this patch with a full log entry with author line,
so sending me that would make it easier to incorporate too.