[Committed, testsuite] Fix PR92870

With my recent commit, I added a test that is not passing on all targets.
My change was valid for targets that have a vector/scalar shift/rotate optabs
(optab that supports vector shifted by scalar).

Since it does not seem to be easy to find out which targets would support it,
I am limiting the test to the targets that I know pass.

gcc/testsuite/ChangeLog

2019-12-12  Sudakshina Das  <sudi.das@arm.com>

	PR testsuite/92870
	* gcc.dg/vect/vect-shift-5.c: Add target to scan-tree-dump.

From-SVN: r279310

gcc/testsuite/ChangeLog

+2019-12-12  Sudakshina Das  <sudi.das@arm.com>
+
+	PR testsuite/92870
+	* gcc.dg/vect/vect-shift-5.c: Add target to scan-tree-dump.
+
 2019-12-12  Ed Schonberg  <schonberg@adacore.com>
 
 	* gnat.dg/warn24.adb: Remove expected warning.

gcc/testsuite/gcc.dg/vect/vect-shift-5.c

@@ -16,4 +16,7 @@ int foo (uint32_t arr[4][4])
     return (((uint16_t)sum) + ((uint32_t)sum >> 16)) >> 1;
 }
 
-/* { dg-final { scan-tree-dump {vectorizable_shift ===[\n\r][^\n]*prologue_cost = 0} "vect" } } */
+/* For a target that has a vector/scalar shift/rotate optab, check
+   that we are not adding the cost of creating a vector from the scalar
+   in the prologue.  */
+/* { dg-final { scan-tree-dump {vectorizable_shift ===[\n\r][^\n]*prologue_cost = 0} "vect" { target { aarch64*-*-* x86_64-*-* } } } } */