Fix memory leak in identify_jump_threads()

	* tree-vrp.c (identify_jump_threads): Delete avail_exprs.

From-SVN: r246415

gcc/ChangeLog

+2017-03-23  Markus Trippelsdorf  <markus@trippelsdorf.de> 
+
+	* tree-vrp.c (identify_jump_threads): Delete avail_exprs.
+
 2017-03-23  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/80032

gcc/tree-vrp.c

@@ -11021,6 +11021,7 @@ identify_jump_threads (void)
      ASSERT_EXPRs are still in the IL and cfg cleanup code does not yet
      handle ASSERT_EXPRs gracefully.  */
   delete equiv_stack;
+  delete avail_exprs;
   delete avail_exprs_stack;
 }