gfortran.h (gfc_option_t): Remove source field.

fortran/
	* gfortran.h (gfc_option_t): Remove source field.  Add
	flag_d_lines field.
	(gfc_new_file): Remove arguments in prototype.
	(gfc_source_file): Make 'const char *'.
	* f95-lang.c (gfc_init): Use gfc_source_file instead of
	gfc_option.source.  Call gfc_new_file without arguments.
	* invoke.texi: Document new options '-fd-lines-as-code' and
	'-fd-lines-as-comment'.
	* lang.opt: Add new options.  Alphabetize.
	* options.c (gfc_init_options): Initialize gfc_source_file instead
	of gfc_option.source.  Initialize gfc_option.flag_d_lines.
	(form_from_filename): Move here from scanner.c.  Make
	'filename' argument 'const'.
	(gfc_post_options): Set gfc_source_file.  Determine source form.
	Warn if 'd-lines*' are used in free form.
	* scanner.c (gfc_source_file): Constify.
	(skip_fixed_comments): Deal with d-lines.
	(get_file): Constify argument 'name'.
	(load_file): Constify argument 'filename'.
	(form_from_filename): Moved to options.c.
	(gfc_new_file): Remove arguments.  Don't initialize
	gfc_source_file, don't determine source form.
	* trans-const.c (gfc_init_constants): Use gfc_source_file instead
	of gfc_option.source.

testsuite/
	* d_lines_1.f, d_lines_2.f, d_lines_3.f, d_lines_4.f,
	d_lines_5.f: New.

From-SVN: r103322