Revert unused optimization in math.pow and implement same code in Dart as is done in the inlined ve…

runtime/vm/intermediate_language.h

 // Copyright (c) 2013, 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_INTERMEDIATE_LANGUAGE_H_
 #define VM_INTERMEDIATE_LANGUAGE_H_
 
 #include "vm/allocation.h"
 #include "vm/ast.h"
 #include "vm/growable_array.h"
@@ skipping 71 matching lines @@
   V(_Double, truncateToDouble, DoubleTruncate, 615732263)                      \
   V(_Double, roundToDouble, DoubleRound, 622146406)                            \
   V(_Double, floorToDouble, DoubleFloor, 1614014643)                           \
   V(_Double, ceilToDouble, DoubleCeil, 277859570)                              \
   V(_Double, _modulo, DoubleMod, 1443289156)                                   \
   V(::, sqrt, MathSqrt, 465520247)                                             \
   V(::, sin, MathSin, 730107143)                                               \
   V(::, cos, MathCos, 1282146521)                                              \
   V(::, min, MathMin, 1022567780)                                              \
   V(::, max, MathMax, 612058870)                                               \
-  V(::, _doublePow, MathDoublePow, 2098142859)                                 \
+  V(::, _doublePow, MathDoublePow, 2125162289)                                 \
   V(Float32x4, Float32x4., Float32x4Constructor, 1314950569)                   \
   V(Float32x4, Float32x4.zero, Float32x4Zero, 1432281809)                      \
   V(Float32x4, Float32x4.splat, Float32x4Splat, 1148280442)                    \
   V(Float32x4, Float32x4.fromInt32x4Bits, Float32x4FromInt32x4Bits,            \
       872145194)                                                               \
   V(Float32x4, Float32x4.fromFloat64x2, Float32x4FromFloat64x2, 1511660322)    \
   V(_Float32x4, shuffle, Float32x4Shuffle, 1178727105)                         \
   V(_Float32x4, shuffleMix, Float32x4ShuffleMix, 927956119)                    \
   V(_Float32x4, get:x, Float32x4ShuffleX, 1351747629)                          \
   V(_Float32x4, get:y, Float32x4ShuffleY, 217416201)                           \
@@ skipping 7679 matching lines @@
   ForwardInstructionIterator* current_iterator_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FlowGraphVisitor);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_INTERMEDIATE_LANGUAGE_H_