i386.c (ix86_avoid_lea_for_addr): Handle zero-extended addresses.

i386.c (ix86_avoid_lea_for_addr): Handle zero-extended addresses.

	* config/i386/i386.c (ix86_avoid_lea_for_addr): Handle
	zero-extended addresses.  Return false if the address has less
	than two components.
	(ix86_split_lea_for_addr): Unconditionally convert target and
	all address operands to requested mode.
	* config/i386/i386.md (*lea<mode>): Recover operands from curr_insn.
	Pass SImode to ix86_split_lea_for_addr when splitting zero-extended
	address.
	(zero-extended add splitter): New splitter to conditionally split
	non-destructive adds.
	(*zero_extendsidi2_rex64): Conditionally emit leal instead of movl.

From-SVN: r189925