PR c++/44282
	* mangle.c (mangle_decl): Always SET_IDENTIFIER_GLOBAL_VALUE.
	(write_CV_qualifiers_for_type): Set G.need_abi_warning.
	(decl_implicit_alias_p): Split out from maybe_remove_implicit_alias.
	* cp-tree.h (DECL_REALLY_EXTERN): Handle null DECL_LANG_SPECIFIC.

From-SVN: r224101