AArch64: Do not increase the vect reduction latency by multiplying count [PR110625]

AArch64: Do not increase the vect reduction latency by multiplying count [PR110625]

The new costs should only count reduction latency by multiplying count for
single_defuse_cycle.  For other situations, this will increase the reduction
latency a lot and miss vectorization opportunities.

Tested on aarch64-linux-gnu.

gcc/ChangeLog:

	PR target/110625
	* config/aarch64/aarch64.cc (count_ops): Only '* count' for
	single_defuse_cycle while counting reduction_latency.

gcc/testsuite/ChangeLog:

	* gcc.target/aarch64/pr110625_1.c: New testcase.
	* gcc.target/aarch64/pr110625_2.c: New testcase.