Implement in-heap backing store for typed arrays.

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 3a540a2722bb79e3194e775072643f195faf47d4..9c0582006a805b0ac6479790a0083d6e03f6a447 100644
--- a/src/arm/lithium-arm.h
+++ b/src/arm/lithium-arm.h
@@ -1590,6 +1590,9 @@ class LLoadKeyed V8_FINAL : public LTemplateInstruction<1, 2, 0> {
   bool is_external() const {
     return hydrogen()->is_external();
   }
+  bool is_fixed_typed_array() const {
+    return hydrogen()->is_fixed_typed_array();
+  }
 
   DECLARE_CONCRETE_INSTRUCTION(LoadKeyed, "load-keyed")
   DECLARE_HYDROGEN_ACCESSOR(LoadKeyed)
@@ -2249,6 +2252,9 @@ class LStoreKeyed V8_FINAL : public LTemplateInstruction<0, 3, 0> {
   }
 
   bool is_external() const { return hydrogen()->is_external(); }
+  bool is_fixed_typed_array() const {
+    return hydrogen()->is_fixed_typed_array();
+  }
   LOperand* elements() { return inputs_[0]; }
   LOperand* key() { return inputs_[1]; }
   LOperand* value() { return inputs_[2]; }