Fix warning breaking profiled bootstrap

This patch fixes an bootstrap error with autoprofiledbootstrap
due to uninitiliazed variables, because the compiler cannot
figure out they don't need to be initialized in an error path.
Just always initialize them.

gcc/:

2016-08-08  Andi Kleen  <ak@linux.intel.com>

	* tree-vrp.c (get_single_symbol): Always initialize inv and neg.

From-SVN: r239266

gcc/ChangeLog

+2016-08-08  Andi Kleen  <ak@linux.intel.com>
+
+	* tree-vrp.c (get_single_symbol): Always initialize inv and neg.
+
 2016-08-08  David Malcolm  <dmalcolm@redhat.com>
 
 	PR c/64955

gcc/tree-vrp.c

@@ -893,6 +893,9 @@ get_single_symbol (tree t, bool *neg, tree *inv)
   bool neg_;
   tree inv_;
 
+  *inv = NULL_TREE;
+  *neg = false;
+
   if (TREE_CODE (t) == PLUS_EXPR
       || TREE_CODE (t) == POINTER_PLUS_EXPR
       || TREE_CODE (t) == MINUS_EXPR)