[Atomics] Make Atomics.exchange a builtin using TF

src/compiler/ia32/instruction-scheduler-ia32.cc

 // Copyright 2015 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.
 
 #include "src/compiler/instruction-scheduler.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
@@ skipping 110 matching lines @@
 
     case kIA32StackCheck:
       return kIsLoadOperation;
 
     case kIA32Push:
     case kIA32PushFloat32:
     case kIA32PushFloat64:
     case kIA32Poke:
       return kHasSideEffect;
 
-    case kIA32Xchgb:
-    case kIA32Xchgw:
-    case kIA32Xchgl:
-      return kIsLoadOperation | kHasSideEffect;
-
 #define CASE(Name) case k##Name:
     COMMON_ARCH_OPCODE_LIST(CASE)
 #undef CASE
       // Already covered in architecture independent code.
       UNREACHABLE();
   }
 
   UNREACHABLE();
   return kNoOpcodeFlags;
 }
@@ skipping 64 matching lines @@
     case kArchTruncateDoubleToI:
       return 9;
     default:
       return 1;
   }
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8