Remove fixed contant pool entries by caching some global constants in Thread

runtime/vm/assembler_x64.h

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_ASSEMBLER_X64_H_
 #define VM_ASSEMBLER_X64_H_
 
 #ifndef VM_ASSEMBLER_H_
 #error Do not include assembler_x64.h directly; use assembler.h instead.
 #endif
@@ skipping 1048 matching lines @@
     intptr_t pc_offset_;
     const String& comment_;
 
     DISALLOW_COPY_AND_ASSIGN(CodeComment);
   };
 
   GrowableArray<CodeComment*> comments_;
   bool allow_constant_pool_;
 
   intptr_t FindImmediate(int64_t imm);
-  bool CanLoadFromObjectPool(const Object& object);
+  bool CanLoadFromObjectPool(const Object& object) const;
   void LoadWordFromPoolOffset(Register dst, Register pp, int32_t offset);
 
   inline void EmitUint8(uint8_t value);
   inline void EmitInt32(int32_t value);
   inline void EmitInt64(int64_t value);
 
   inline void EmitRegisterREX(Register reg, uint8_t rex);
   inline void EmitOperandREX(int rm, const Operand& operand, uint8_t rex);
   inline void EmitXmmRegisterOperand(int rm, XmmRegister reg);
   inline void EmitFixup(AssemblerFixup* fixup);
@@ skipping 120 matching lines @@
 }
 
 
 inline void Assembler::EmitOperandSizeOverride() {
   EmitUint8(0x66);
 }
 
 }  // namespace dart
 
 #endif  // VM_ASSEMBLER_X64_H_