Add optimization for pow(base, 0.5) to the other architectures as well.

tests/lib/math/double_pow_test.dart

 // Copyright (c) 2011, 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.
+// VMOptions=--optimization-counter-threshold=5
 
 library math_test;
 import "package:expect/expect.dart";
 import 'dart:math';
 
 void checkVeryClose(double a, double b) {
   // We find a ulp (unit in the last place) by shifting the original number
   // to the right. This only works if we are not too close to infinity or if
   // we work with denormals.
   // We special case or 0.0, but not for infinity.
@@ skipping 32 matching lines @@
   -0.5,  // Non-integer, magnitude < 1.
   -0.0,
   0.5,  // Non-integer, magnitude < 1.
   1.0,  // Unit
   1.5,  // Non-integer, magnitude > 1
   2.0,  // Even integer
   3.0,  // Odd integer
   Infinity
 ];
 
-main() {
+test() {
   // Tests of pow(x, y):
   for (var d in samples) {
     // if `y` is zero (0.0 or -0.0), the result is always 1.0.
     Expect.identical(1.0, pow(d, 0.0), "$d");
     Expect.identical(1.0, pow(d, -0.0), "$d");
   }
   for (var d in samples) {
     // if `x` is 1.0, the result is always 1.0.
     Expect.identical(1.0, pow(1.0, d), "$d");
   }
@@ skipping 82 matching lines @@
   // Underflow.
   Expect.identical(0.0, pow(10.0, -325.0));
 
   // Conversion to double.
 
   // The second argument is an odd integer as int, but not when converted
   // to double.
   Expect.identical(Infinity, pow(-0.0, -9223372036854775809));
 }
 
+main() {
+  for (int i = 0; i < 10; i++) test();
+}