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

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

Index: src/compiler/ia32/instruction-selector-ia32.cc
diff --git a/src/compiler/ia32/instruction-selector-ia32.cc b/src/compiler/ia32/instruction-selector-ia32.cc
index cb208f08106672e3b433556caf6e7fb35f1f8936..0d5cf4ed48a4861321b2c4ad62acccc395e822ad 100644
--- a/src/compiler/ia32/instruction-selector-ia32.cc
+++ b/src/compiler/ia32/instruction-selector-ia32.cc
@@ -1565,14 +1565,6 @@
        g.UseRegister(left), g.Use(right));
 }
 
-void InstructionSelector::VisitAtomicLoad(Node* node) {
-  LoadRepresentation load_rep = LoadRepresentationOf(node->op());
-  DCHECK(load_rep.representation() == MachineRepresentation::kWord8 ||
-         load_rep.representation() == MachineRepresentation::kWord16 ||
-         load_rep.representation() == MachineRepresentation::kWord32);
-  USE(load_rep);
-  VisitLoad(node);
-}
 
 // static
 MachineOperatorBuilder::Flags