[testsuite] Add test for PR91532

[Prathamesh Kulkarni]

Hi Richard,
Sorry for not adding the test in PR91532 fix.
Is the attached patch OK to commit ?

Thanks,
Prathamesh

2019-10-18  Prathamesh Kulkarni  <prathamesh.kulka...@linaro.org>

        PR tree-optimization/91532
testsuite/
        * gcc.target/aarch64/sve/fmla_2.c: Add dg-scan check for deleted store.

diff --git a/gcc/testsuite/gcc.target/aarch64/sve/fmla_2.c 
b/gcc/testsuite/gcc.target/aarch64/sve/fmla_2.c
index 5c04bcdb3f5..bebb073d1f8 100644
--- a/gcc/testsuite/gcc.target/aarch64/sve/fmla_2.c
+++ b/gcc/testsuite/gcc.target/aarch64/sve/fmla_2.c
@@ -1,4 +1,4 @@
-/* { dg-options "-O3" } */
+/* { dg-options "-O3 -fdump-tree-ifcvt-details" } */
 
 #include <stdint.h>
 
@@ -15,5 +15,6 @@ f (double *restrict a, double *restrict b, double *restrict c,
     }
 }
 
+/* { dg-final { scan-tree-dump-times "Deleted dead store" 1 "ifcvt" } } */
 /* { dg-final { scan-assembler-times {\tfmla\tz[0-9]+\.d, p[0-7]/m, 
z[0-9]+\.d, z[0-9]+\.d\n} 2 } } */
 /* { dg-final { scan-assembler-not {\tfmad\t} } } */