arm: testsuite: Adapt mve-vabs.c to improved codegen

Since commit r15-491-gc290e6a0b7a9de this failure happens on
armv8l-linux-gnueabihf and arm-eabi:

Running gcc:gcc.target/arm/simd/simd.exp ...
gcc.target/arm/simd/mve-vabs.c: memmove found 0 times
FAIL: gcc.target/arm/simd/mve-vabs.c scan-assembler-times memmove 3

In PR PR target/116010, Andrew Pinski noted that
"gcc.target/arm/simd/mve-vabs.c now calls memcpy because of the restrict
instead of memmove. That should be a simple fix there."

Therefore change the test to expect memcpy rather than memmove.

Another change is that memcpy is inlined rather than called, so also change
the test to check the optimized tree dump rather than the generated
assembly.

Tested on armv8l-linux-gnueabihf and arm-eabi.

gcc/testsuite/ChangeLog:
	PR target/116010
	* gcc.target/arm/simd/mve-vabs.c: Test tree dump and adjust to new
	code.

Suggested-by: Andrew Pinski <quic_apinski@quicinc.com>