Adds intrinsics for Float64Array [] and []=.

runtime/vm/assembler_arm64.h

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_ASSEMBLER_ARM64_H_
 #define VM_ASSEMBLER_ARM64_H_
 
 #ifndef VM_ASSEMBLER_H_
 #error Do not include assembler_arm64.h directly; use assembler.h instead.
 #endif
@@ skipping 1201 matching lines @@
 
   // Inlined allocation of an instance of class 'cls', code has no runtime
   // calls. Jump to 'failure' if the instance cannot be allocated here.
   // Allocated instance is returned in 'instance_reg'.
   // Only the tags field of the object is initialized.
   void TryAllocate(const Class& cls,
                    Label* failure,
                    Register instance_reg,
                    Register pp);
 
+  Address ElementAddressForIntIndex(bool is_external,
+                                    intptr_t cid,
+                                    intptr_t index_scale,
+                                    Register array,
+                                    intptr_t index) const;
+  Address ElementAddressForRegIndex(bool is_load,
+                                    bool is_external,
+                                    intptr_t cid,
+                                    intptr_t index_scale,
+                                    Register array,
+                                    Register index);
+
  private:
   AssemblerBuffer buffer_;  // Contains position independent code.
 
   // Objects and patchable jump targets.
   GrowableObjectArray& object_pool_;
 
   // Patchability of pool entries.
   GrowableArray<Patchability> patchable_pool_entries_;
 
   // Pair type parameter for DirectChainedHashMap.
@@ skipping 441 matching lines @@
                                   Register value,
                                   Label* no_update);
 
   DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(Assembler);
 };
 
 }  // namespace dart
 
 #endif  // VM_ASSEMBLER_ARM64_H_