Conditionally compile support for --enable-mapped_location.

Conditionally compile support for --enable-mapped_location.

	* basic-block.h (struct edge_def):  Use new source_locus typedef.
	* c-common.c (fname_decl):  Update save/clear/store of input_location.
	(c_do_switch_warnings):  Update for USE_MAPPED_LOCATION case.
	* c-decl.c:  Likewise.
	* c-dump.c (dump_stmt):  Likewise.
	* c-gimplify.c (c-gimplify.c):  Generalize using SET_EXPR_LOCATION.
	* c-lex.c (cb_line_change):  If USE_MAPPED_LOCATION use token's	src_loc
	to set input_location direction, rather than using linemap_lookup.
	(fe_file_change, cb_def_pragma):  Again use source_location directly.
	* c-opts.c (saved_lineno):  Remove static variable.
	(c_common_post_options, c_common_init):  Don't bothner to save,
	clear and restore input_Location - now handled by lang_dependent_init.
	* function.c (init_function_start):  Use new DECL_IS_BUILTIN macro.
	* xcoffout.c (xcoff_assign_fundamental_type_number):  Likewise.

From-SVN: r83919