8066775: opto/node.hpp:355, assert(i < _max) failed: oob: i=1, _max=1

Summary: bad assumption on graph shape in CastIINode::Value if that part of the graph is becoming dead.
Reviewed-by: kvn

src/share/vm/opto/connode.cpp

@@ -462,7 +462,8 @@ const Type *CastIINode::Value(PhaseTransform *phase) const {
   // Try to improve the type of the CastII if we recognize a CmpI/If
   // pattern.
   if (_carry_dependency) {
-    if (in(0) != NULL && (in(0)->is_IfFalse() || in(0)->is_IfTrue())) {
+    if (in(0) != NULL && in(0)->in(0) != NULL && in(0)->in(0)->is_If()) {
+      assert(in(0)->is_IfFalse() || in(0)->is_IfTrue(), "should be If proj");
       Node* proj = in(0);
       if (proj->in(0)->in(1)->is_Bool()) {
         Node* b = proj->in(0)->in(1);