gcc/
* configure.ac (gcc_gxx_include_dir): Use $(libsubdir_to_prefix).
(gcc_tooldir): Likewise.
* configure: Regenerate.
* Makefile.in (libsubdir_to_prefix): New variable, based on the
old configure.ac gcc_tooldir setting.
(prefix_to_exec_prefix): New variable.
(DRIVER_DEFINES): Use $(libsubdir_to_prefix)$(prefix_to_exec_prefix)
rather than $(unlibsubdir)/../ to derive TOOLDIR_BASE_PREFIX.
From-SVN: r126225
