[aarch64] [testsuite] tolerate alternate insn selection [PR121599]

On gcc-14, instead of 'movi\td[0-9]*,#0', we select
'mov\tz[0-9]*\.b,#0', and the testcase fails.
As in pfalse* tests, tolerate the difference.

for  gcc/testsuite/ChangeLog

	PR target/121599
	* gcc.target/aarch64/sve2/pr121599.c: Tolerate alterate insn
	selection.

(cherry picked from commit ba653cb0d26e004c10d20ebd9f009a0a823659b0)