testsuite: Require vect_shift in gcc.dg/vect/pr112325.c [PR115303]

testsuite: Require vect_shift in gcc.dg/vect/pr112325.c [PR115303]

The new gcc.dg/vect/pr112325.c test FAILs on Solaris/SPARC:

FAIL: gcc.dg/vect/pr112325.c -flto -ffat-lto-objects  scan-tree-dump-times vect "vectorized 1 loops" 1
FAIL: gcc.dg/vect/pr112325.c scan-tree-dump-times vect "vectorized 1 loops" 1

As analyzed in the PR, the test requires vect_shift, so this patch adds
that requirement.

Tested on i386-pc-solaris2.11 and sparc-sun-solaris2.11.

2024-06-03  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>

	gcc/testsuite:
	PR tree-optimization/115303
	* gcc.dg/vect/pr112325.c: Require vect_shift.