[Atomics] code stubs for atomic operations

src/code-stubs.h

Index: src/code-stubs.h
diff --git a/src/code-stubs.h b/src/code-stubs.h
index ae0c1e9172f99e7ca259e2102196ed5d12d0fa5f..e672dee73e4841981941d8ef5e335885109fc897 100644
--- a/src/code-stubs.h
+++ b/src/code-stubs.h
@@ -23,6 +23,7 @@ namespace internal {
   /* PlatformCodeStubs */                   \
   V(ArgumentsAccess)                        \
   V(ArrayConstructor)                       \
+  V(AtomicsLoad)                            \
   V(BinaryOpICWithAllocationSite)           \
   V(CallApiFunction)                        \
   V(CallApiAccessor)                        \
@@ -2978,6 +2979,15 @@ class StringCompareStub : public PlatformCodeStub {
 };
 
 
+class AtomicsLoadStub : public PlatformCodeStub {
+ public:
+  explicit AtomicsLoadStub(Isolate* isolate) : PlatformCodeStub(isolate) {}
+
+  DEFINE_CALL_INTERFACE_DESCRIPTOR(AtomicsLoad);
+  DEFINE_PLATFORM_CODE_STUB(AtomicsLoad, PlatformCodeStub);
+};
+
+
 #undef DEFINE_CALL_INTERFACE_DESCRIPTOR
 #undef DEFINE_PLATFORM_CODE_STUB
 #undef DEFINE_HANDLER_CODE_STUB