Remove lang_type_ptrmem.

Remove lang_type_ptrmem.

Changlogs:
	cp/
	Remove lang_type_ptrmem.
	* cp-tree.h (lang_type_header): Remove is_lang_type_class. Move
	into ...
	(lang_type_class): ... this.  Reorder bitfields.  Rename to ...
	(lang_type): ... this.  Delete old definition.
	(lang_type_ptrmem): Delete.
	(LANG_TYPE_CLASS_CHECK): Simply get TYPE_LANG_SPECIFIC.  Adjust
	uses.
	(LANG_TYPE_PTRMEM_CHECK): Delete.
	(TYPE_GET_PTRMEMFUNC_TYPE, TYPE_SET_PTRMEMFUNC_TYPE): Delete.
	(TYPE_PTRMEMFUNC_TYPE): New.  Use TYPE_LANG_SLOT_1.
	* decl.c (build_ptrmemfunc_type): Adjust.
	* lex.c (copy_lang_type): Remove lang_type_ptrmem handling.
	(maybe_add_lang_type_raw): Don't set u.c.h.is_lang_type_class.

	objcp/
	* objcp-decl.h (SIZEOF_OBJC_TYPE_LANG_SPECIFIC): Use lang_type.
	(ALLOC_OBJC_TYPE_LANG_SPECIFIC): Use it.  Don't set
	u.c.h.is_lang_type_class.

From-SVN: r248827