* cp-tree.def: Add SRCLOC.
	* cp-tree.h: Add struct tree_srcloc and accessor macros.
	* tree.c (build_srcloc, build_srcloc_here): New fns.
	* pt.c (add_pending_template): Use build_srcloc_here.
	(push_tinst_level): Update last_template_error_tick before erroring.
	(instantiate_decl): Restore lineno and input_filename before
	calling add_pending_template.
	* decl2.c (finish_file): Set up lineno and input_filename for
	pending templates.

From-SVN: r19967