re PR target/53447 (missed optimization of 64bit ALU operation with small constant)

	PR target/53447
	* config/arm/arm-protos.h (const_ok_for_dimode_op): New prototype.
	* config/arm/arm.c (const_ok_for_dimode_op): New function.
	* config/arm/constraints.md (Dd): New constraint.
	* config/arm/predicates.md (arm_adddi_operand): New predicate.
	* config/arm/arm.md (adddi3): Extend it to handle constants.
	(arm_adddi3): Likewise.
	(addsi3_carryin_<optab>): Extend it to handle sbc case.
	(addsi3_carryin_alt2_<optab>): Likewise.
	* config/arm/neon.md (adddi3_neon): Extend it to handle constants.

	* gcc.target/arm/pr53447-1.c: New testcase.
	* gcc.target/arm/pr53447-2.c: New testcase.
	* gcc.target/arm/pr53447-3.c: New testcase.
	* gcc.target/arm/pr53447-4.c: New testcase.

From-SVN: r189102