[committed] Add testcase for already fixed PR tree-optimization/85794

[Jakub Jelinek]

Hi!

This testcase has been fixed by the PR85793 fix r260317.
I've committed following test as obvious so that we can close the PR.

2018-11-22  Jakub Jelinek  <ja...@redhat.com>

        PR tree-optimization/85794
        * gcc.dg/vect/O3-pr85794.c: New test.

--- gcc/testsuite/gcc.dg/vect/O3-pr85794.c.jj   2018-11-22 17:49:10.898893803 
+0100
+++ gcc/testsuite/gcc.dg/vect/O3-pr85794.c      2018-11-22 17:47:04.261981744 
+0100
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+
+int a, b, *c, d;
+int *f[6];
+
+void
+foo (void)
+{
+  for (b = 1; b >= 0; b--)
+    for (d = 0; d <= 3; d++)
+      a |= f[b * 5] != c;
+}

        Jakub