cp-tree.def (LOOKUP_EXPR): Document.

cp-tree.def (LOOKUP_EXPR): Document.

	* cp-tree.def (LOOKUP_EXPR): Document.  Remove second argument.
	* cp-tree.h (DECL_TI_TEMPLATE): Improve documentation.
	* lex.c (do_identifier): Don't use a second argument, or a type,
	when building LOOKUP_EXPRs.
	(do_identifier): Likewise.
	(do_scoped_id): Likewise.
	* method.c (hack_identifier): Improve error message.
	* pt.c (lookup_template_function): Don't needlessly call
	copy_to_permanent or build_min.
	(tsubst_copy): Remove #if 0'd code.  Tsubst into LOOKUP_EXPRs if
	necessary.
	(do_decl_instantiation): Improve error message.
	* tree.c (mapcar, case LOOKUP_EXPR): Don't be sorry; make a copy.
	(build_min): Copy the type to the permanent obstack, too.

From-SVN: r21544