[Atomics] code stubs for atomic operations

src/builtins.cc

Index: src/builtins.cc
diff --git a/src/builtins.cc b/src/builtins.cc
index e05a4dd45a98a38c8fc11e8f95f4ca1685a769cd..fa55f7723edabe52e40af31179ab7cce24290adb 100644
--- a/src/builtins.cc
+++ b/src/builtins.cc
@@ -9,6 +9,7 @@
 #include "src/arguments.h"
 #include "src/base/once.h"
 #include "src/bootstrapper.h"
+#include "src/compiler/code-stub-assembler.h"
 #include "src/dateparser-inl.h"
 #include "src/elements.h"
 #include "src/frames-inl.h"
@@ -4170,6 +4171,20 @@ void Builtins::Generate_StackCheck(MacroAssembler* masm) {
 }
 
 
+void Builtins::Generate_AtomicsLoadCheck(MacroAssembler* masm) {
+  using namespace compiler;
+  Isolate* isolate = masm->isolate();
+  Zone zone;
+  BuiltinDescriptor descriptor(isolate);
+  CodeStubAssembler assembler(isolate, &zone, descriptor, Code::STUB,

[Jarin, 2016/02/03 09:04:07]

Code::Stub ==> Code::ComputeFlags(Code::STUB)

[binji, 2016/02/03 22:09:02]

Oops. Would have been nice if the compiler caught that.

+                              "AtomicsLoadCheck");
+
+  assembler.Return(assembler.StackArgOrUndefined(assembler.Parameter(0), 1));
+
+  masm->Jump(assembler.GenerateCode(), RelocInfo::CODE_TARGET);
+}
+
+
 #define DEFINE_BUILTIN_ACCESSOR_C(name, ignore)               \
 Handle<Code> Builtins::name() {                               \
   Code** code_address =                                       \