[Atomics] Remove Atomics code stubs; use TF ops

src/compiler/mips64/instruction-selector-mips64.cc

Index: src/compiler/mips64/instruction-selector-mips64.cc
diff --git a/src/compiler/mips64/instruction-selector-mips64.cc b/src/compiler/mips64/instruction-selector-mips64.cc
index 6680a49ff91f15a2e42e9ca4bf440fe806501e07..bca523d0df7f5cff7abb3efa967801a6d2ed4917 100644
--- a/src/compiler/mips64/instruction-selector-mips64.cc
+++ b/src/compiler/mips64/instruction-selector-mips64.cc
@@ -1963,6 +1963,9 @@ void InstructionSelector::VisitFloat64InsertHighWord32(Node* node) {
        g.UseRegister(left), g.UseRegister(right));
 }
 
+void InstructionSelector::VisitAtomicLoad(Node* node) {
+  // TODO(binji)
+}
 
 // static
 MachineOperatorBuilder::Flags