Revert of [Atomics] Remove Atomics code stubs; use TF ops

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
@@ skipping 60 matching lines @@
   V(CheckedLoadWord32)                    \
   V(CheckedLoadWord64)                    \
   V(CheckedLoadFloat32)                   \
   V(CheckedLoadFloat64)                   \
   V(CheckedStoreWord8)                    \
   V(CheckedStoreWord16)                   \
   V(CheckedStoreWord32)                   \
   V(CheckedStoreWord64)                   \
   V(CheckedStoreFloat32)                  \
   V(CheckedStoreFloat64)                  \
-  V(ArchStackSlot)                        \
-  V(AtomicLoadInt8)                       \
-  V(AtomicLoadUint8)                      \
-  V(AtomicLoadInt16)                      \
-  V(AtomicLoadUint16)                     \
-  V(AtomicLoadWord32)
+  V(ArchStackSlot)
 
 #define ARCH_OPCODE_LIST(V)  \
   COMMON_ARCH_OPCODE_LIST(V) \
   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
@@ skipping 80 matching lines @@
 typedef BitField<AddressingMode, 8, 5> AddressingModeField;
 typedef BitField<FlagsMode, 13, 2> FlagsModeField;
 typedef BitField<FlagsCondition, 15, 5> FlagsConditionField;
 typedef BitField<int, 20, 12> MiscField;
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_INSTRUCTION_CODES_H_