(early draft) Strict mode - throw exception on assignment to read only property.

src/x64/stub-cache-x64.cc

Index: src/x64/stub-cache-x64.cc
diff --git a/src/x64/stub-cache-x64.cc b/src/x64/stub-cache-x64.cc
index c27e1b8c42addcd2c527541a7044a3c5360e0525..584d0c0b167867694db16f36d8807e73dfd95f76 100644
--- a/src/x64/stub-cache-x64.cc
+++ b/src/x64/stub-cache-x64.cc
@@ -3490,10 +3490,15 @@ MaybeObject* ExternalArrayStubCompiler::CompileKeyedStoreStub(
   __ push(rdx);  // receiver
   __ push(rcx);  // key
   __ push(rax);  // value
+  __ Push(Smi::FromInt(NONE));   // PropertyAttributes
+  __ Push(Smi::FromInt(
+      Code::ExtractExtraICStateFromFlags(flags) == kStrictMode
+        ? kStrictMode
+        : kNonStrictMode));
   __ push(rbx);  // return address
 
   // Do tail-call to runtime routine.
-  __ TailCallRuntime(Runtime::kSetProperty, 3, 1);
+  __ TailCallRuntime(Runtime::kSetProperty, 5, 1);
 
   return GetCode(flags);
 }