[turbofan] Turn weaken min/max limits for typer into constants.

src/compiler/typer.h

 // 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.
 
 #ifndef V8_COMPILER_TYPER_H_
 #define V8_COMPILER_TYPER_H_
 
 #include "src/compiler/graph.h"
-#include "src/compiler/opcodes.h"
 #include "src/types.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 // Forward declarations.
 class LazyTypeCache;
 
 
@@ skipping 36 matching lines @@
   Type* truish;
   Type* integer;
   Type* weakint;
   Type* number_fun0_;
   Type* number_fun1_;
   Type* number_fun2_;
   Type* weakint_fun1_;
   Type* random_fun_;
   LazyTypeCache* cache_;
 
-  ZoneVector<double> weaken_min_limits_;
-  ZoneVector<double> weaken_max_limits_;
   DISALLOW_COPY_AND_ASSIGN(Typer);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_TYPER_H_