rs6000: Fix one more vec_splat case

This fixes the one remaining case where the stricter vec_splat checking
complains in the testsuite.


	* g++.dg/ext/altivec-6.C: Change the vec_splat second argument to a
	valid value, in the "vector bool int" case.

From-SVN: r264681

gcc/testsuite/ChangeLog

+2018-09-27  Segher Boessenkool  <segher@kernel.crashing.org>
+
+	* g++.dg/ext/altivec-6.C: Change the vec_splat second argument to a
+	valid value, in the "vector bool int" case.
+
 2018-09-27  Uros Bizjak  <ubizjak@gmail.com>
 
 	* gcc.dg/rtl/x86_64/dfinit.c: Update scan-rtl-dump string.

gcc/testsuite/g++.dg/ext/altivec-6.C

@@ -26,5 +26,5 @@ void foo(void) {
    elements in the referenced vector.  */
   vbs = vec_splat(vbs, 4);
   vp = vec_splat(vp, 1);
-  vbi = vec_splat(vbi, 15);  
+  vbi = vec_splat(vbi, 3);  
 }