Disallow subclassing Arrays.

src/mips64/code-stubs-mips64.cc

Index: src/mips64/code-stubs-mips64.cc
diff --git a/src/mips64/code-stubs-mips64.cc b/src/mips64/code-stubs-mips64.cc
index c952a8acf0cac59650fe7177c30756d419f2a6fd..5509dde33b9852c51a1c08c60cc01be7535db397 100644
--- a/src/mips64/code-stubs-mips64.cc
+++ b/src/mips64/code-stubs-mips64.cc
@@ -2886,6 +2886,7 @@ void CallIC_ArrayStub::Generate(MacroAssembler* masm) {
   __ Branch(&miss, ne, a5, Operand(at));
 
   __ mov(a2, a4);
+  __ mov(a3, a1);
   ArrayConstructorStub stub(masm->isolate(), arg_count());
   __ TailCallStub(&stub);
 
@@ -4842,6 +4843,7 @@ 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
   // -----------------------------------
@@ -4864,6 +4866,9 @@ void ArrayConstructorStub::Generate(MacroAssembler* masm) {
     __ AssertUndefinedOrAllocationSite(a2, a4);
   }
 
+  Label subclassing;
+  __ Branch(&subclassing, ne, a1, Operand(a3));
+
   Label no_info;
   // Get the elements kind and case on that.
   __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
@@ -4877,6 +4882,9 @@ void ArrayConstructorStub::Generate(MacroAssembler* masm) {
 
   __ bind(&no_info);
   GenerateDispatchToArrayStub(masm, DISABLE_ALLOCATION_SITES);
+
+  __ bind(&subclassing);
+  __ TailCallRuntime(Runtime::kThrowArrayNotSubclassableError, 0, 1);
 }