* cse.c: (find_best_addr): Don't call copy_rtx before calling
	fold_rtx.  Save cost recomputation if fold_rtx did nothing.
	(fold_rtx) <ASM_OPERANDS>: Don't do anything if INSN is
	NULL_RTX.

Co-Authored-By: Kazu Hirata <kazu@cs.umass.edu>

From-SVN: r94345