PR c++/12909
	* mangle.c: Include cgraph.h.
	(mangle_decl): If the mangled name will change in a later
	ABI version, make the later mangled name an alias.
	* method.c (make_alias_for): Copy DECL_ARGUMENTS.
	* Make-lang.in (mangle.o): Depend on cgraph.h.

From-SVN: r157201