[Atomics] Remove Atomics code stubs; use TF ops

src/mips64/code-stubs-mips64.cc

Index: src/mips64/code-stubs-mips64.cc
diff --git a/src/mips64/code-stubs-mips64.cc b/src/mips64/code-stubs-mips64.cc
index 2dda3deab434a2b260c255373d0a193d5a7a9e37..7f0db4f4b9f2fef39e3119edf3c8f4283f6cf3b4 100644
--- a/src/mips64/code-stubs-mips64.cc
+++ b/src/mips64/code-stubs-mips64.cc
@@ -5755,10 +5755,6 @@ void CallApiGetterStub::Generate(MacroAssembler* masm) {
                            return_value_operand, NULL);
 }
 
-void AtomicsLoadStub::Generate(MacroAssembler* masm) {
-  // TODO(binji)
-}
-
 #undef __
 
 }  // namespace internal