Add an autoconf option for mangling Mesa.

In addition to setting up the flags correctly, this renames the
generated libraries to ensure they get 'Mangled' in the name.
This is very useful for distros and the like, where mangled Mesa
and non-mangled GL libraries typically need to be installed
side-by-side.

Reviewed-by: Dan Nicholson <dbn.lists@gmail.com>
2 files changed