[Atomics] Remove Atomics code stubs; use TF ops

src/compiler/code-assembler.cc

Index: src/compiler/code-assembler.cc
diff --git a/src/compiler/code-assembler.cc b/src/compiler/code-assembler.cc
index f75ed852dd68fe9c15542f04ebce6a3af9b7015c..2fc6d96bcff4b4a638968099b760d8952c6d7e56 100644
--- a/src/compiler/code-assembler.cc
+++ b/src/compiler/code-assembler.cc
@@ -201,6 +201,13 @@ Node* CodeAssembler::TruncateFloat64ToInt32JavaScript(Node* a) {
   return raw_assembler_->TruncateFloat64ToInt32(TruncationMode::kJavaScript, a);
 }
 
+Node* CodeAssembler::ChangeUint32ToWord(Node* value) {
+  if (raw_assembler_->machine()->Is64()) {
+    value = raw_assembler_->ChangeUint32ToUint64(value);
+  }
+  return value;
+}
+
 #define DEFINE_CODE_ASSEMBLER_UNARY_OP(name) \
   Node* CodeAssembler::name(Node* a) { return raw_assembler_->name(a); }
 CODE_ASSEMBLER_UNARY_OP_LIST(DEFINE_CODE_ASSEMBLER_UNARY_OP)
@@ -355,6 +362,10 @@ Node* CodeAssembler::Load(MachineType rep, Node* base, Node* index) {
   return raw_assembler_->Load(rep, base, index);
 }
 
+Node* CodeAssembler::AtomicLoad(MachineType rep, Node* base, Node* index) {
+  return raw_assembler_->AtomicLoad(rep, base, index);
+}
+
 Node* CodeAssembler::Store(MachineRepresentation rep, Node* base, Node* value) {
   return raw_assembler_->Store(rep, base, value, kFullWriteBarrier);
 }