PR fortran/33502
	* scanner.c (gfc_advance_line): Call debug_hooks->end_source_file
	and debug_hooks->start_source_file when appropriate, and set
	dbg_emitted.
	(gfc_define_undef_line): New function.
	(load_file): Don't error out on #define and #undef lines.
	* parse.c (next_statement): Call gfc_define_undef_line.
	(gfc_parse_file): Call debug_hooks->start_source_file and
	debug_hooks->end_source_file for the main source file if
	required.
	* gfortran.h (gfc_linebuf): Add dbg_emitted field.
	(gfc_define_undef_line): New prototype.

From-SVN: r129011