Support double allocations when folding allocation.

src/hydrogen-instructions.h

Index: src/hydrogen-instructions.h
diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index 763b6369e3583a0a1c9b1a41bd3af7e93e8fe34e..2d1ff9e95f2de3014befc563c9d93ceb66e1af38 100644
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -5070,9 +5070,13 @@ class HAllocate: public HTemplateInstruction<2> {
 
 class HInnerAllocatedObject: public HTemplateInstruction<1> {
  public:
-  HInnerAllocatedObject(HValue* value, int offset, HType type = HType::Tagged())
+  HInnerAllocatedObject(HValue* value,
+                        int offset,
+                        HType type = HType::Tagged(),
+                        bool double_alignment = false)
       : offset_(offset),
-        type_(type) {
+        type_(type),
+        double_alignment_(double_alignment) {
     ASSERT(value->IsAllocate());
     SetOperandAt(0, value);
     set_representation(Representation::Tagged());
@@ -5089,11 +5093,16 @@ class HInnerAllocatedObject: public HTemplateInstruction<1> {
 
   virtual void PrintDataTo(StringStream* stream);
 
+  bool MustAllocateDoubleAligned() {
+    return double_alignment_;
+  }
+
   DECLARE_CONCRETE_INSTRUCTION(InnerAllocatedObject)
 
  private:
   int offset_;
   HType type_;
+  bool double_alignment_;
 };