Rename MathNatives_2atan to MathNatives_atan2.

runtime/vm/bootstrap_natives.h

 // Copyright (c) 2012, 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_BOOTSTRAP_NATIVES_H_
 #define VM_BOOTSTRAP_NATIVES_H_
 
 #include "vm/native_entry.h"
 
 // bootstrap dart natives used in the core dart library.
@@ skipping 67 matching lines @@
   V(String_toLowerCase, 1)                                                     \
   V(String_toUpperCase, 1)                                                     \
   V(Strings_concatAll, 1)                                                      \
   V(MathNatives_sqrt, 1)                                                       \
   V(MathNatives_sin, 1)                                                        \
   V(MathNatives_cos, 1)                                                        \
   V(MathNatives_tan, 1)                                                        \
   V(MathNatives_asin, 1)                                                       \
   V(MathNatives_acos, 1)                                                       \
   V(MathNatives_atan, 1)                                                       \
-  V(MathNatives_2atan, 2)                                                      \
+  V(MathNatives_atan2, 2)                                                      \
   V(MathNatives_exp, 1)                                                        \
   V(MathNatives_log, 1)                                                        \
   V(MathNatives_random, 0)                                                     \
   V(MathNatives_parseInt, 1)                                                   \
   V(MathNatives_parseDouble, 1)                                                \
   V(DateNatives_currentTimeMillis, 0)                                          \
   V(DateNatives_timeZoneName, 1)                                               \
   V(DateNatives_timeZoneOffsetInSeconds, 1)                                    \
   V(DateNatives_localTimeZoneAdjustmentInSeconds, 0)                           \
   V(AssertionError_throwNew, 2)                                                \
@@ skipping 90 matching lines @@
   V(GrowableObjectArray_getLength, 1)                                          \
   V(GrowableObjectArray_getCapacity, 1)                                        \
   V(GrowableObjectArray_setLength, 2)                                          \
   V(GrowableObjectArray_setData, 2)                                            \
 
 BOOTSTRAP_NATIVE_LIST(DECLARE_NATIVE_ENTRY)
 
 }  // namespace dart
 
 #endif  // VM_BOOTSTRAP_NATIVES_H_