api accessor store ics should return passed value

src/a64/code-stubs-a64.cc

Index: src/a64/code-stubs-a64.cc
diff --git a/src/a64/code-stubs-a64.cc b/src/a64/code-stubs-a64.cc
index 269b97f41c17fe8d4107bceb1fbaf832977aabeb..40aa0b617a4b5a625150126c4fe2cbae8a47bf68 100644
--- a/src/a64/code-stubs-a64.cc
+++ b/src/a64/code-stubs-a64.cc
@@ -5581,7 +5581,7 @@ void CallApiFunctionStub::Generate(MacroAssembler* masm) {
   Register context = cp;
 
   int argc = ArgumentBits::decode(bit_field_);
-  bool restore_context = RestoreContextBits::decode(bit_field_);
+  bool is_store = IsStoreBits::decode(bit_field_);
   bool call_data_undefined = CallDataUndefinedBits::decode(bit_field_);
 
   typedef FunctionCallbackArguments FCA;
@@ -5654,8 +5654,10 @@ void CallApiFunctionStub::Generate(MacroAssembler* masm) {
   AllowExternalCallThatCantCauseGC scope(masm);
   MemOperand context_restore_operand(
       fp, (2 + FCA::kContextSaveIndex) * kPointerSize);
-  MemOperand return_value_operand(fp,
-                                  (2 + FCA::kReturnValueOffset) * kPointerSize);
+  // Stores return the first js argument
+  int return_value_offset =
+      2 + (is_store ? FCA::kArgsLength : FCA::kReturnValueOffset);
+  MemOperand return_value_operand(fp, return_value_offset * kPointerSize);
 
   const int spill_offset = 1 + kApiStackSpace;
   __ CallApiFunctionAndReturn(api_function_address,
@@ -5663,8 +5665,7 @@ void CallApiFunctionStub::Generate(MacroAssembler* masm) {
                               kStackUnwindSpace,
                               spill_offset,
                               return_value_operand,
-                              restore_context ?
-                                  &context_restore_operand : NULL);
+                              &context_restore_operand);
 }