[turbofan] Remove the unused asm.js types from TypeCache.

src/compiler/operation-typer.h

 // Copyright 2016 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.
 
 #ifndef V8_COMPILER_OPERATION_TYPER_H_
 #define V8_COMPILER_OPERATION_TYPER_H_
 
 #include "src/base/flags.h"
 #include "src/compiler/opcodes.h"
 
 namespace v8 {
 namespace internal {
 
+// Forward declarations.
 class Isolate;
 class RangeType;
 class Type;
-class TypeCache;
 class Zone;
 
 namespace compiler {
 
+// Forward declarations.
 class Operator;
+class TypeCache;
 
 class OperationTyper {
  public:
   OperationTyper(Isolate* isolate, Zone* zone);
 
   // Typing Phi.
   Type* Merge(Type* left, Type* right);
 
   Type* ToPrimitive(Type* type);
 
@@ skipping 50 matching lines @@
   Type* singleton_the_hole_;
   Type* signed32ish_;
   Type* unsigned32ish_;
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_OPERATION_TYPER_H_