S/390: Add IBM z13 pipeline description

S/390: Add IBM z13 pipeline description

This patch adds proper support for the -mtune=z13 option by adding a
z13 pipeline description.  As started with zEC12 we mostly make use of
the sched reorder hooks to implement a grouping strategy.  However,
this time we also keep an eye at the instruction mix provided in the
out of order window to allow the hardware to exploit the different
units.

gcc/ChangeLog:

	* config/s390/2827.md: Rename ooo_* insn attributes to zEC12_*.
	* config/s390/2964.md: New file.
	* config/s390/s390.c (s390_get_sched_attrmask): Use the right set
	of insn grouping attributes depending on the CPU level.
	(s390_get_unit_mask): New function.
	(s390_sched_score): Remove the OOO from the scheduling macros.
	Add loop to calculate a score for the instruction mix.
	(s390_sched_reorder): Likewise plus improve debug output.
	(s390_sched_variable_issue): Rename macros as above.  Calculate
	the unit distances after actually scheduling an insn.  Improve
	debug output.
	(s390_sched_init): Clear last_scheduled_unit_distance array.
	* config/s390/s390.md: Include 2964.md.

From-SVN: r233548