[libstdc++] Un-precious the CC-related variables

[Richard Sandiford]

Andreas Jaeger <aj@suse.de> writes:
> Phil Edwards <phil@jaj.com> writes:
> > Folks are finding that we have to remove the "precious variable" protection
> > from CC, like I did with CXX et al.  This should help with the multilibs
> > problems until multilibs get moved to the top level, although I don't have
> > x86_64 or irix systems to verify that.
> 
> Thanks, this seems to fix it for me on x86_64,

And for me on irix, thanks.

Richard