[testsuite] Fix PR94019 to check vector char when vect_hw_misalign

As PR94019 shows, without misaligned vector access support but with
realign load, the vectorized loop will end up with realign scheme.
It generates mask (control vector) with return type vector signed
char which breaks the not check.

gcc/testsuite/ChangeLog

2020-03-09  Kewen Lin  <linkw@gcc.gnu.org>

    PR testsuite/94019
    * gcc.dg/vect/vect-over-widen-17.c: Don't expect vector char if
    it's without misaligned vector access support.

gcc/testsuite/ChangeLog

 2020-03-09  Kewen Lin  <linkw@gcc.gnu.org>
 
+	PR testsuite/94019
+	* gcc.dg/vect/vect-over-widen-17.c: Don't expect vector char if it's
+	without misaligned vector access support.
+
+2020-03-09  Kewen Lin  <linkw@gcc.gnu.org>
+
 	PR testsuite/94023
 	* gcc.dg/vect/slp-perm-12.c: Expect loop vectorized messages only on
 	vect_hw_misalign targets.

gcc/testsuite/gcc.dg/vect/vect-over-widen-17.c

@@ -41,6 +41,9 @@ main (void)
 }
 
 /* { dg-final { scan-tree-dump-not {vect_recog_over_widening_pattern: detected} "vect" } } */
-/* { dg-final { scan-tree-dump-not {vector[^\n]*char} "vect" } } */
+/* On Power, if there is no vect_hw_misalign support, unaligned vector access
+   adopts realign_load scheme.  It requires rs6000_builtin_mask_for_load to
+   generate mask whose return type is vector char.  */
+/* { dg-final { scan-tree-dump-not {vector[^\n]*char} "vect" { target vect_hw_misalign } } } */
 /* { dg-final { scan-tree-dump-not {vector[^ ]* int} "vect" } } */
 /* { dg-final { scan-tree-dump-times "vectorized 1 loop" 1 "vect" } } */