don't run dart gen on JS patch code

test/dart_codegen/expect/math/math

Index: test/dart_codegen/expect/math/math
diff --git a/test/dart_codegen/expect/math/math b/test/dart_codegen/expect/math/math
index c410873645cf35c503184a228b3535c84279a14f..88443a483f94e5ea1ab16e4a9b5c58a65af86a74 100644
--- a/test/dart_codegen/expect/math/math
+++ b/test/dart_codegen/expect/math/math
@@ -47,161 +47,14 @@ num max(num a, num b) {
   if (b == 0 && a.isNegative) return b;
   return a;
 }
-double atan2(num a, num b) => ((__x13) => DDC$RT.cast(__x13, dynamic, double,
-    "CastGeneral", """line 150, column 6 of dart:math: """, __x13 is double,
-    true))(JS('double', r'Math.atan2(#, #)', checkNum(a), checkNum(b)));
-num pow(num x, num exponent) {
-  checkNum(x);
-  checkNum(exponent);
-  return ((__x14) => DDC$RT.cast(__x14, dynamic, num, "CastGeneral",
-      """line 192, column 10 of dart:math: """, __x14 is num,
-      true))(JS('num', r'Math.pow(#, #)', x, exponent));
-}
-double sin(num x) => ((__x15) => DDC$RT.cast(__x15, dynamic, double,
-    "CastGeneral", """line 201, column 6 of dart:math: """, __x15 is double,
-    true))(JS('double', r'Math.sin(#)', checkNum(x)));
-double cos(num x) => ((__x16) => DDC$RT.cast(__x16, dynamic, double,
-    "CastGeneral", """line 209, column 6 of dart:math: """, __x16 is double,
-    true))(JS('double', r'Math.cos(#)', checkNum(x)));
-double tan(num x) => ((__x17) => DDC$RT.cast(__x17, dynamic, double,
-    "CastGeneral", """line 219, column 6 of dart:math: """, __x17 is double,
-    true))(JS('double', r'Math.tan(#)', checkNum(x)));
-double acos(num x) => ((__x18) => DDC$RT.cast(__x18, dynamic, double,
-    "CastGeneral", """line 228, column 6 of dart:math: """, __x18 is double,
-    true))(JS('double', r'Math.acos(#)', checkNum(x)));
-double asin(num x) => ((__x19) => DDC$RT.cast(__x19, dynamic, double,
-    "CastGeneral", """line 236, column 6 of dart:math: """, __x19 is double,
-    true))(JS('double', r'Math.asin(#)', checkNum(x)));
-double atan(num x) => ((__x20) => DDC$RT.cast(__x20, dynamic, double,
-    "CastGeneral", """line 243, column 6 of dart:math: """, __x20 is double,
-    true))(JS('double', r'Math.atan(#)', checkNum(x)));
-double sqrt(num x) => ((__x21) => DDC$RT.cast(__x21, dynamic, double,
-    "CastGeneral", """line 251, column 6 of dart:math: """, __x21 is double,
-    true))(JS('double', r'Math.sqrt(#)', checkNum(x)));
-double exp(num x) => ((__x22) => DDC$RT.cast(__x22, dynamic, double,
-    "CastGeneral", """line 259, column 6 of dart:math: """, __x22 is double,
-    true))(JS('double', r'Math.exp(#)', checkNum(x)));
-double log(num x) => ((__x23) => DDC$RT.cast(__x23, dynamic, double,
-    "CastGeneral", """line 267, column 6 of dart:math: """, __x23 is double,
-    true))(JS('double', r'Math.log(#)', checkNum(x)));
-const int _POW2_32 = 0x100000000;
-class _JSRandom implements Random {
-  const _JSRandom();
-  int nextInt(int max) {
-    if (max <= 0 || max > _POW2_32) {
-      throw new RangeError("max must be in range 0 < max ≤ 2^32, was $max");
-    }
-    return ((__x24) => DDC$RT.cast(__x24, dynamic, int, "CastGeneral",
-        """line 278, column 12 of dart:math: """, __x24 is int,
-        true))(JS("int", "(Math.random() * #) >>> 0", max));
-  }
-  double nextDouble() => ((__x25) => DDC$RT.cast(__x25, dynamic, double,
-      "CastGeneral", """line 285, column 26 of dart:math: """, __x25 is double,
-      true))(JS("double", "Math.random()"));
-  bool nextBool() => ((__x26) => DDC$RT.cast(__x26, dynamic, bool,
-      "CastGeneral", """line 290, column 22 of dart:math: """, __x26 is bool,
-      true))(JS("bool", "Math.random() < 0.5"));
-}
-class _Random implements Random {
-  static const double _POW2_53_D = 1.0 * (0x20000000000000);
-  static const double _POW2_27_D = 1.0 * (1 << 27);
-  static const int _MASK32 = 0xFFFFFFFF;
-  int _lo = 0;
-  int _hi = 0;
-  _Random(int seed) {
-    int empty_seed = 0;
-    if (seed < 0) {
-      empty_seed = -1;
-    }
-    do {
-      int low = seed & _MASK32;
-      seed = (seed - low) ~/ _POW2_32;
-      int high = seed & _MASK32;
-      seed = (seed - high) ~/ _POW2_32;
-      int tmplow = low << 21;
-      int tmphigh = (high << 21) | (low >> 11);
-      tmplow = (~low & _MASK32) + tmplow;
-      low = tmplow & _MASK32;
-      high = (~high + tmphigh + ((tmplow - low) ~/ 0x100000000)) & _MASK32;
-      tmphigh = high >> 24;
-      tmplow = (low >> 24) | (high << 8);
-      low ^= tmplow;
-      high ^= tmphigh;
-      tmplow = low * 265;
-      low = tmplow & _MASK32;
-      high = (high * 265 + (tmplow - low) ~/ 0x100000000) & _MASK32;
-      tmphigh = high >> 14;
-      tmplow = (low >> 14) | (high << 18);
-      low ^= tmplow;
-      high ^= tmphigh;
-      tmplow = low * 21;
-      low = tmplow & _MASK32;
-      high = (high * 21 + (tmplow - low) ~/ 0x100000000) & _MASK32;
-      tmphigh = high >> 28;
-      tmplow = (low >> 28) | (high << 4);
-      low ^= tmplow;
-      high ^= tmphigh;
-      tmplow = low << 31;
-      tmphigh = (high << 31) | (low >> 1);
-      tmplow += low;
-      low = tmplow & _MASK32;
-      high = (high + tmphigh + (tmplow - low) ~/ 0x100000000) & _MASK32;
-      tmplow = _lo * 1037;
-      _lo = tmplow & _MASK32;
-      _hi = (_hi * 1037 + (tmplow - _lo) ~/ 0x100000000) & _MASK32;
-      _lo ^= low;
-      _hi ^= high;
-    } while (seed != empty_seed);
-    if (_hi == 0 && _lo == 0) {
-      _lo = 0x5A17;
-    }
-    _nextState();
-    _nextState();
-    _nextState();
-    _nextState();
-  }
-  void _nextState() {
-    int tmpHi = 0xFFFF0000 * _lo;
-    int tmpHiLo = tmpHi & _MASK32;
-    int tmpHiHi = tmpHi - tmpHiLo;
-    int tmpLo = 0xDA61 * _lo;
-    int tmpLoLo = tmpLo & _MASK32;
-    int tmpLoHi = tmpLo - tmpLoLo;
-    int newLo = tmpLoLo + tmpHiLo + _hi;
-    _lo = newLo & _MASK32;
-    int newLoHi = newLo - _lo;
-    _hi = ((tmpLoHi + tmpHiHi + newLoHi) ~/ _POW2_32) & _MASK32;
-    assert(_lo < _POW2_32);
-    assert(_hi < _POW2_32);
-  }
-  int nextInt(int max) {
-    if (max <= 0 || max > _POW2_32) {
-      throw new RangeError("max must be in range 0 < max ≤ 2^32, was $max");
-    }
-    if ((max & (max - 1)) == 0) {
-      _nextState();
-      return _lo & (max - 1);
-    }
-    int rnd32;
-    int result;
-    do {
-      _nextState();
-      rnd32 = _lo;
-      result = ((__x27) => DDC$RT.cast(__x27, num, int, "CastGeneral",
-          """line 424, column 16 of dart:math: """, __x27 is int,
-          true))(rnd32.remainder(max));
-    } while ((rnd32 - result + max) >= _POW2_32);
-    return result;
-  }
-  double nextDouble() {
-    _nextState();
-    int bits26 = _lo & ((1 << 26) - 1);
-    _nextState();
-    int bits27 = _lo & ((1 << 27) - 1);
-    return (bits26 * _POW2_27_D + bits27) / _POW2_53_D;
-  }
-  bool nextBool() {
-    _nextState();
-    return (_lo & 1) == 0;
-  }
-}
+external double atan2(num a, num b);
+external num pow(num x, num exponent);
+external double sin(num x);
+external double cos(num x);
+external double tan(num x);
+external double acos(num x);
+external double asin(num x);
+external double atan(num x);
+external double sqrt(num x);
+external double exp(num x);
+external double log(num x);