Fix memento initialization when constructing from new call

src/mips/builtins-mips.cc

Index: src/mips/builtins-mips.cc
diff --git a/src/mips/builtins-mips.cc b/src/mips/builtins-mips.cc
index 0af1ce09a2a3ed171e2d7283a035348ae7e3f3fc..6d625d87649dc93e570e27daab8d8c1b01eddd09 100644
--- a/src/mips/builtins-mips.cc
+++ b/src/mips/builtins-mips.cc
@@ -337,14 +337,11 @@ static void Generate_JSConstructStubHelper(MacroAssembler* masm,
   {
     FrameScope scope(masm, StackFrame::CONSTRUCT);
 
-    if (create_memento) {
-      __ AssertUndefinedOrAllocationSite(a2, t0);
-      __ push(a2);
-    }
-
     // Preserve the incoming parameters on the stack.
+    __ AssertUndefinedOrAllocationSite(a2, t0);
+    __ push(a2);
     __ SmiTag(a0);
-    __ Push(a0, a1, a3);
+    __ Push(a2, a0, a1, a3);
 
     // Try to allocate the object without transitioning into C code. If any of
     // the preconditions is not met, the code bails out to the runtime call.
@@ -476,7 +473,8 @@ static void Generate_JSConstructStubHelper(MacroAssembler* masm,
         __ sw(t7, MemOperand(t5));
         __ Addu(t5, t5, kPointerSize);
         // Load the AllocationSite.
-        __ lw(t7, MemOperand(sp, 2 * kPointerSize));
+        __ lw(t7, MemOperand(sp, 3 * kPointerSize));
+        __ AssertUndefinedOrAllocationSite(a2, t0);
         DCHECK_EQ(1 * kPointerSize, AllocationMemento::kAllocationSiteOffset);
         __ sw(t7, MemOperand(t5));
         __ Addu(t5, t5, kPointerSize);
@@ -659,12 +657,12 @@ void Builtins::Generate_JSConstructStubForDerived(MacroAssembler* masm) {
   //  -- sp[...]: constructor arguments
   // -----------------------------------
 
-  // TODO(dslomov): support pretenuring
-  CHECK(!FLAG_pretenuring_call_new);
-
   {
     FrameScope frame_scope(masm, StackFrame::CONSTRUCT);
 
+    __ AssertUndefinedOrAllocationSite(a2, t0);
+    __ push(a2);
+
     __ mov(t0, a0);
     __ SmiTag(t0);
     __ push(t0);  // Smi-tagged arguments count.