New I/O specifiers CARRIAGECONTROL, READONLY, SHARE with -fdec.

	gcc/fortran/
	* gfortran.texi: Document.
	* frontend-passes.c (gfc_code_walker): Add SHARE and CARRIAGECONTROL.
	* io.c (gfc_free_open, gfc_resolve_open, gfc_match_open): Ditto.
	* gfortran.h (gfc_open): Add SHARE, CARRIAGECONTROL, and READONLY.
	* io.c (io_tag, match_open_element): Ditto.
	* ioparm.def: Ditto.
	* trans-io.c (gfc_trans_open): Ditto.
	* io.c (match_dec_etag, match_dec_ftag): New functions.

	libgfortran/io/
	* libgfortran.h (IOPARM_OPEN_HAS_READONLY, IOPARM_OPEN_HAS_SHARE,
	IOPARM_OPEN_HAS_CC): New for READONLY, SHARE, and CARRIAGECONTROL.
	* close.c (st_close): Support READONLY.
	* io.h (st_parameter_open, unit_flags): Support SHARE, CARRIAGECONTROL,
	and READONLY.
	* open.c (st_open): Ditto.
	* transfer.c (data_transfer_init): Ditto.
	* io.h (st_parameter_dt): New member 'cc' for CARRIAGECONTROL.
	* write.c (write_check_cc, write_cc): New functions for CARRIAGECONTROL.
	* transfer.c (next_record_cc): Ditto.
	* file_pos.c (st_endfile): Support SHARE and CARRIAGECONTROL.
	* io.h (st_parameter_inquire): Ditto.
	* open.c (edit_modes, new_unit): Ditto.
	* inquire.c (inquire_via_unit, inquire_via_filename): Ditto.
	* io.h (unit_share, unit_cc, cc_fortran, IOPARM_INQUIRE_HAS_SHARE,
	IOPARM_INQUIRE_HAS_CC): New for SHARE and CARRIAGECONTROL.
	* open.c (share_opt, cc_opt): Ditto.
	* read.c (read_x): Support CARRIAGECONTROL.
	* transfer.c (read_sf, next_record_r, next_record_w): Ditto.
	* write.c (list_formatted_write_scalar, write_a): Ditto.
	* unix.h (close_share): New prototype.
	* unix.c (open_share, close_share): New functions to handle SHARE.
	* unix.c (open_external): Handle READONLY. Call open_share.
	* close.c (st_close): Call close_share.

	gcc/testsuite/
	* dec_io_1.f90: New test.
        * dec_io_2.f90: New test.
        * dec_io_3.f90: New test.
        * dec_io_4.f90: New test.
        * dec_io_5.f90: New test.
        * dec_io_6.f90: New test.

From-SVN: r241550