aarch64: Add optimization for ADD (ABS (A), B) intrinsics

gcc/ChangeLog:

	* config/aarch64/aarch64-simd.md (*aarch64_abs_plus<mode>): New
	define_insn_and_split.

gcc/testsuite/ChangeLog:

	* gcc.target/aarch64/add_abs.c: New test.
2 files changed