[PATCH] Fix segfault on verify_dominators error path

[Alan Modra]

Committed as obvious.  If the next check also fails, an attempt is
made to print imm_bb->index.

        * dominance.c (verify_dominators): Don't segfault on NULL imm_bb.

Index: gcc/dominance.c
===================================================================
--- gcc/dominance.c     (revision 236843)
+++ gcc/dominance.c     (working copy)
@@ -1024,6 +1024,7 @@
        {
          error ("dominator of %d status unknown", bb->index);
          err = true;
+         continue;
        }
 
       basic_block imm_bb_correct = di.get_idom (bb);

-- 
Alan Modra
Australia Development Lab, IBM