[Atomics] Make Atomics.exchange a builtin using TF

src/compiler/x64/instruction-scheduler-x64.cc

Index: src/compiler/x64/instruction-scheduler-x64.cc
diff --git a/src/compiler/x64/instruction-scheduler-x64.cc b/src/compiler/x64/instruction-scheduler-x64.cc
index 427e58083f6dd672ea6b9c259cc9a9eefbf2233c..30b6a68518871bd92cf549d3fc1931afdbaf43a0 100644
--- a/src/compiler/x64/instruction-scheduler-x64.cc
+++ b/src/compiler/x64/instruction-scheduler-x64.cc
@@ -178,11 +178,6 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kX64Poke:
       return kHasSideEffect;
 
-    case kX64Xchgb:
-    case kX64Xchgw:
-    case kX64Xchgl:
-      return kIsLoadOperation | kHasSideEffect;

[binji, 2017/01/17 21:45:50]

Where did this move to?

[aseemgarg, 2017/01/21 08:40:37]

These are removed. Instead we are now relying on the the common exchange
instructions (see instruction-scheduler.h)

-
 #define CASE(Name) case k##Name:
     COMMON_ARCH_OPCODE_LIST(CASE)
 #undef CASE