m68hc11.c (m6812_cost): Make cost of add higher than a shift to avoid adding a register with itself.

	* config/m68hc11/m68hc11.c (m6812_cost): Make cost of add higher
	than a shift to avoid adding a register with itself.
	(m68hc11_memory_move_cost): Take into account NO_REGS.
	(m68hc11_register_move_cost): Update and use memory move cost
	for soft registers.
	(m68hc11_address_cost): Make cost of valid offset not 0 so that
	it gives more opportunities to cse to optimize.
	* config/m68hc11/m68hc11.h (REGISTER_MOVE_COST): Pass the mode.
	* config/m68hc11/m68hc11-protos.h (m68hc11_register_move_cost): Update.

From-SVN: r50833