Array length reduction should throw in strict mode if it can't delete an element.

src/arm/code-stubs-arm.cc

Index: src/arm/code-stubs-arm.cc
diff --git a/src/arm/code-stubs-arm.cc b/src/arm/code-stubs-arm.cc
index 0dd399ea2c6b6430b325f70e648c07cd5ae66aee..f21a8bbb1a9ba7f42a12ed3b108eaf63df27a8f8 100644
--- a/src/arm/code-stubs-arm.cc
+++ b/src/arm/code-stubs-arm.cc
@@ -5377,34 +5377,39 @@ void CallApiAccessorStub::Generate(MacroAssembler* masm) {
 
 void CallApiGetterStub::Generate(MacroAssembler* masm) {
   // ----------- S t a t e -------------
-  //  -- sp[0]                  : name
-  //  -- sp[4 - kArgsLength*4]  : PropertyCallbackArguments object
+  //  -- sp[0]                        : name
+  //  -- sp[4 .. (4 + kArgsLength*4)] : v8::PropertyCallbackInfo::args_
   //  -- ...
-  //  -- r2                     : api_function_address
+  //  -- r2                           : api_function_address
   // -----------------------------------
 
   Register api_function_address = ApiGetterDescriptor::function_address();
   DCHECK(api_function_address.is(r2));
 
-  __ mov(r0, sp);  // r0 = Handle<Name>
-  __ add(r1, r0, Operand(1 * kPointerSize));  // r1 = PCA
+  // v8::PropertyCallbackInfo::args_ array and name handle.
+  const int kStackUnwindSpace = PropertyCallbackArguments::kArgsLength + 1;
+
+  // Load address of v8::PropertyAccessorInfo::args_ array and name handle.
+  __ mov(r0, sp);                             // r0 = Handle<Name>
+  __ add(r1, r0, Operand(1 * kPointerSize));  // r1 = v8::PCI::args_
 
   const int kApiStackSpace = 1;
   FrameScope frame_scope(masm, StackFrame::MANUAL);
   __ EnterExitFrame(false, kApiStackSpace);
 
-  // Create PropertyAccessorInfo instance on the stack above the exit frame with
-  // r1 (internal::Object** args_) as the data.
+  // Create v8::PropertyCallbackInfo object on the stack and initialize
+  // it's args_ field.
   __ str(r1, MemOperand(sp, 1 * kPointerSize));
-  __ add(r1, sp, Operand(1 * kPointerSize));  // r1 = AccessorInfo&
-
-  const int kStackUnwindSpace = PropertyCallbackArguments::kArgsLength + 1;
+  __ add(r1, sp, Operand(1 * kPointerSize));  // r1 = v8::PropertyCallbackInfo&
 
   ExternalReference thunk_ref =
       ExternalReference::invoke_accessor_getter_callback(isolate());
+
+  // +3 is to skip prolog, return address and name handle.
+  MemOperand return_value_operand(
+      fp, (PropertyCallbackArguments::kReturnValueOffset + 3) * kPointerSize);
   CallApiFunctionAndReturn(masm, api_function_address, thunk_ref,
-                           kStackUnwindSpace, NULL,
-                           MemOperand(fp, 6 * kPointerSize), NULL);
+                           kStackUnwindSpace, NULL, return_value_operand, NULL);
 }