Disallow subclassing Arrays.

src/mips/code-stubs-mips.cc

Index: src/mips/code-stubs-mips.cc
diff --git a/src/mips/code-stubs-mips.cc b/src/mips/code-stubs-mips.cc
index 74705f97efdd8947c992589abb81974d574a789d..795469998372545bfe05ac0d0f58c1ea4c7bd947 100644
--- a/src/mips/code-stubs-mips.cc
+++ b/src/mips/code-stubs-mips.cc
@@ -2808,6 +2808,7 @@ void CallIC_ArrayStub::Generate(MacroAssembler* masm) {
   __ Branch(&miss, ne, t1, Operand(at));
 
   __ mov(a2, t0);
+  __ mov(a3, a1);
   ArrayConstructorStub stub(masm->isolate(), arg_count());
   __ TailCallStub(&stub);
 
@@ -4799,6 +4800,7 @@ void ArrayConstructorStub::Generate(MacroAssembler* masm) {
   //  -- a0 : argc (only if argument_count() == ANY)
   //  -- a1 : constructor
   //  -- a2 : AllocationSite or undefined
+  //  -- a3 : Original constructor
   //  -- sp[0] : return address
   //  -- sp[4] : last argument
   // -----------------------------------
@@ -4821,6 +4823,9 @@ void ArrayConstructorStub::Generate(MacroAssembler* masm) {
     __ AssertUndefinedOrAllocationSite(a2, t0);
   }
 
+  Label subclassing;
+  __ Branch(&subclassing, ne, a1, Operand(a3));
+
   Label no_info;
   // Get the elements kind and case on that.
   __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
@@ -4834,6 +4839,9 @@ void ArrayConstructorStub::Generate(MacroAssembler* masm) {
 
   __ bind(&no_info);
   GenerateDispatchToArrayStub(masm, DISABLE_ALLOCATION_SITES);
+
+  __ bind(&subclassing);
+  __ TailCallRuntime(Runtime::kThrowArrayNotSubclassableError, 0, 1);
 }