PR c++/63942
	* name-lookup.c (supplement_binding_1): Override a mangling alias.
	* mangle.c (implicit_alias_p, remove_implicit_alias): New.
	(mangle_decl): Avoid creating conflicting alias with
	-fabi-compat-version=0, too.
	* cp-tree.h: Adjust.

From-SVN: r217950