Replace OStream with std::ostream.

src/compiler/instruction-codes.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_INSTRUCTION_CODES_H_
 #define V8_COMPILER_INSTRUCTION_CODES_H_
 
+#include <iosfwd>
+
 #if V8_TARGET_ARCH_ARM
 #include "src/compiler/arm/instruction-codes-arm.h"
 #elif V8_TARGET_ARCH_ARM64
 #include "src/compiler/arm64/instruction-codes-arm64.h"
 #elif V8_TARGET_ARCH_IA32
 #include "src/compiler/ia32/instruction-codes-ia32.h"
 #elif V8_TARGET_ARCH_X64
 #include "src/compiler/x64/instruction-codes-x64.h"
 #else
 #define TARGET_ARCH_OPCODE_LIST(V)
 #define TARGET_ADDRESSING_MODE_LIST(V)
 #endif
 #include "src/utils.h"
 
 namespace v8 {
 namespace internal {
-
-class OStream;
-
 namespace compiler {
 
 // Target-specific opcodes that specify which assembly sequence to emit.
 // Most opcodes specify a single instruction.
 #define ARCH_OPCODE_LIST(V) \
   V(ArchCallCodeObject)     \
   V(ArchCallJSFunction)     \
   V(ArchJmp)                \
   V(ArchNop)                \
   V(ArchRet)                \
   V(ArchTruncateDoubleToI)  \
   TARGET_ARCH_OPCODE_LIST(V)
 
 enum ArchOpcode {
 #define DECLARE_ARCH_OPCODE(Name) k##Name,
   ARCH_OPCODE_LIST(DECLARE_ARCH_OPCODE)
 #undef DECLARE_ARCH_OPCODE
 #define COUNT_ARCH_OPCODE(Name) +1
   kLastArchOpcode = -1 ARCH_OPCODE_LIST(COUNT_ARCH_OPCODE)
 #undef COUNT_ARCH_OPCODE
 };
 
-OStream& operator<<(OStream& os, const ArchOpcode& ao);
+std::ostream& operator<<(std::ostream& os, const ArchOpcode& ao);
 
 // Addressing modes represent the "shape" of inputs to an instruction.
 // Many instructions support multiple addressing modes. Addressing modes
 // are encoded into the InstructionCode of the instruction and tell the
 // code generator after register allocation which assembler method to call.
 #define ADDRESSING_MODE_LIST(V) \
   V(None)                       \
   TARGET_ADDRESSING_MODE_LIST(V)
 
 enum AddressingMode {
 #define DECLARE_ADDRESSING_MODE(Name) kMode_##Name,
   ADDRESSING_MODE_LIST(DECLARE_ADDRESSING_MODE)
 #undef DECLARE_ADDRESSING_MODE
 #define COUNT_ADDRESSING_MODE(Name) +1
   kLastAddressingMode = -1 ADDRESSING_MODE_LIST(COUNT_ADDRESSING_MODE)
 #undef COUNT_ADDRESSING_MODE
 };
 
-OStream& operator<<(OStream& os, const AddressingMode& am);
+std::ostream& operator<<(std::ostream& os, const AddressingMode& am);
 
 // The mode of the flags continuation (see below).
 enum FlagsMode { kFlags_none = 0, kFlags_branch = 1, kFlags_set = 2 };
 
-OStream& operator<<(OStream& os, const FlagsMode& fm);
+std::ostream& operator<<(std::ostream& os, const FlagsMode& fm);
 
 // The condition of flags continuation (see below).
 enum FlagsCondition {
   kEqual,
   kNotEqual,
   kSignedLessThan,
   kSignedGreaterThanOrEqual,
   kSignedLessThanOrEqual,
   kSignedGreaterThan,
   kUnsignedLessThan,
   kUnsignedGreaterThanOrEqual,
   kUnsignedLessThanOrEqual,
   kUnsignedGreaterThan,
   kUnorderedEqual,
   kUnorderedNotEqual,
   kUnorderedLessThan,
   kUnorderedGreaterThanOrEqual,
   kUnorderedLessThanOrEqual,
   kUnorderedGreaterThan,
   kOverflow,
   kNotOverflow
 };
 
-OStream& operator<<(OStream& os, const FlagsCondition& fc);
+std::ostream& operator<<(std::ostream& os, const FlagsCondition& fc);
 
 // The InstructionCode is an opaque, target-specific integer that encodes
 // what code to emit for an instruction in the code generator. It is not
 // interesting to the register allocator, as the inputs and flags on the
 // instructions specify everything of interest.
 typedef int32_t InstructionCode;
 
 // Helpers for encoding / decoding InstructionCode into the fields needed
 // for code generation. We encode the instruction, addressing mode, and flags
 // continuation into a single InstructionCode which is stored as part of
 // the instruction.
 typedef BitField<ArchOpcode, 0, 7> ArchOpcodeField;
 typedef BitField<AddressingMode, 7, 5> AddressingModeField;
 typedef BitField<FlagsMode, 12, 2> FlagsModeField;
 typedef BitField<FlagsCondition, 14, 5> FlagsConditionField;
 typedef BitField<int, 14, 18> MiscField;
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_INSTRUCTION_CODES_H_