Allow specifying base offset when constructing Keyed hydrogen instructions

src/arm/lithium-arm.h

Index: src/arm/lithium-arm.h
diff --git a/src/arm/lithium-arm.h b/src/arm/lithium-arm.h
index b333095c7933cffc6292ef63b24b2d2c1301e80c..714ec55e2a984f0b58ec2600e1accfccb4046511 100644
--- a/src/arm/lithium-arm.h
+++ b/src/arm/lithium-arm.h
@@ -1648,7 +1648,7 @@ class LLoadKeyed V8_FINAL : public LTemplateInstruction<1, 2, 0> {
   DECLARE_HYDROGEN_ACCESSOR(LoadKeyed)
 
   virtual void PrintDataTo(StringStream* stream) V8_OVERRIDE;
-  uint32_t additional_index() const { return hydrogen()->index_offset(); }
+  uint32_t base_offset() const { return hydrogen()->base_offset(); }
 };
 
 
@@ -2223,7 +2223,7 @@ class LStoreKeyed V8_FINAL : public LTemplateInstruction<0, 3, 0> {
     }
     return hydrogen()->NeedsCanonicalization();
   }
-  uint32_t additional_index() const { return hydrogen()->index_offset(); }
+  uint32_t base_offset() const { return hydrogen()->base_offset(); }
 };