IRA: Use minimal cost for hard register movement

IRA: Use minimal cost for hard register movement

This is the 2nd attempt to fix PR90706.  IRA calculates wrong AVR
costs for moving general hard regs of SFmode.  This was the reason for
spilling a pseudo in the PR.  In this patch we use smaller move cost
of hard reg in its natural and operand modes.

        PR rtl-optimization/90706

gcc/ChangeLog:

	* ira-costs.cc: Include print-rtl.h.
	(record_reg_classes, scan_one_insn): Add code to print debug info.
	(record_operand_costs): Find and use smaller cost for hard reg
	move.

gcc/testsuite/ChangeLog:

	* gcc.target/avr/pr90706.c: New.