sparc: Add scheduling information for LEON5

The LEON5 can often dual issue instructions from the same 64-bit aligned
double word if there are no data dependencies. Add scheduling information
to avoid scheduling unpairable instructions back-to-back.

gcc/ChangeLog:

	* config/sparc/sparc-opts.h (enum sparc_processor_type): Add LEON5
	* config/sparc/sparc.c (struct processor_costs): Add LEON5 costs
	(leon5_adjust_cost): Increase cost of store with data dependency
	on ALU instruction and FPU anti-dependencies.
	(sparc_option_override): Add LEON5 costs
	(sparc_adjust_cost): Add LEON5 cost adjustments
	* config/sparc/sparc.h: Add LEON5
	* config/sparc/sparc.md: Include LEON5 scheduling information
	* config/sparc/sparc.opt: Add LEON5
	* doc/invoke.texi: Add LEON5
	* config/sparc/leon5.md: New file.