PR other/46020
* configure.ac (CXX_FOR_TARGET): Add -funconfigured-libstdc++-v3.
* Makefile.def (CXX_FOR_TARGET): Removed from flags_to_pass.
* Makefile.tpl (CXX_FOR_TARGET_FLAG_TO_PASS): New.
(BASE_FLAGS_TO_PASS): Use it.
* configure: Rebuilt.
* Makefile.in: Rebuilt.

From-SVN: r167160