fix global variable alignment for testcase gcc.dg/torture/pr96133.c

The testcase was errorneously accessing the global variable via a
type that might require bigger alignment than provided.  Fix that
via an appropriate attribute.

2020-07-13  Richard Biener  <rguenther@suse.de>

	PR testsuite/96180
	* gcc.dg/torture/pr96133.c: Align global variable.

(cherry picked from commit 7a4770f0394751860ee54520b23007938907ac33)

gcc/testsuite/gcc.dg/torture/pr96133.c

 /* { dg-do run } */
 
 typedef int T;
-static const T a[2][3] = { { 1, 2, 3 }, { 4, 5, 6 } };
+static const T a[2][3] __attribute__((aligned(2*sizeof(T)))) = { { 1, 2, 3 }, { 4, 5, 6 } };
 typedef T v2 __attribute__((vector_size(2*sizeof(T))));
 
 int