* cp-tree.h (struct lang_type): Added has_mutable flag.
	(CLASSTYPE_HAS_MUTABLE): New macro to access it.
	(TYPE_HAS_MUTABLE_P): New macro to read it.
	(cp_has_mutable_p): Prototype for new function.
	* class.c (finish_struct_1): Set has_mutable from members.
	* decl.c (cp_finish_decl): Clear decl's TREE_READONLY flag, if
	it contains a mutable.
	* typeck.c (cp_has_mutable_p): New function.
Fixes g++.other/mutable1.C

From-SVN: r24701