[turbofan] Always check that we make progress in the Typer.

src/compiler/typer.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/typer.h"
 
 #include "src/base/flags.h"
 #include "src/base/lazy-instance.h"
 #include "src/bootstrapper.h"
 #include "src/compiler/common-operator.h"
@@ skipping 243 matching lines @@
 
   Reduction UpdateType(Node* node, Type* current) {
     if (NodeProperties::IsTyped(node)) {
       // Widen the type of a previously typed node.
       Type* previous = NodeProperties::GetType(node);
       if (node->opcode() == IrOpcode::kPhi) {
         // Speed up termination in the presence of range types:
         current = Weaken(node, current, previous);
       }
 
-      DCHECK(previous->Is(current));
+      CHECK(previous->Is(current));
 
       NodeProperties::SetType(node, current);
-      if (!(previous->Is(current) && current->Is(previous))) {
+      if (!current->Is(previous)) {
         // If something changed, revisit all uses.
         return Changed(node);
       }
       return NoChange();
     } else {
       // No previous type, simply update the type.
       NodeProperties::SetType(node, current);
       return Changed(node);
     }
   }
@@ skipping 1828 matching lines @@
   }
   if (Type::IsInteger(*value)) {
     return Type::Range(value->Number(), value->Number(), zone());
   }
   return Type::Constant(value, zone());
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8