Update new test to check asserts only if they are enabled and remove VM option.

tests/standalone/fixed_precision_double_test.dart

 // Copyright (c) 2016, 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=--enable_asserts
 
 import "package:expect/expect.dart";
 
 bool testAssociativity(Function f) {
   // Example from https://en.wikipedia.org/wiki/Floating_point
   // Test that (a + b) + c == a + (b + c).
   double a = f(1234.567);  // Chop literals.
   double b = f(45.67834);
   double c = f(0.0004);
   double x = (a + b) + c;  // Chop result of multiplication or division only.
@@ skipping 14 matching lines @@
   print("x: $x");
   print("y: $y");
   return x == y;
 }
 
 // Simulate precision checking with assert.
 assertP(double d) {
   assert(d == d.p);
 }
 
+bool assertionsEnabled() {
+  try {
+    assert(false);
+    return false;
+  } on AssertionError catch (e) {
+    return true;
+  }
+  return false;
+}
+
 main() {
   // The getter p keeps only 20 (by default) bits after the decimal point.
   Expect.equals(0.0, 0.0.p);  // 0.0 has no 1-bit after the decimal point.
   Expect.equals(1.5, 1.5.p);  // 1.5 has a single 1-bit after the decimal point.
   Expect.notEquals(1.1, 1.1.p);  // 1.1 has many 1-bits after the decimal point.
   Expect.notEquals(1/3, (1/3).p);  // 0.33333333... ditto.
 
   Expect.equals(1.1 + 1/3, 1/3 + 1.1);  // Test addition commutativity.
   Expect.equals(1.1.p + (1/3).p, (1/3).p + 1.1.p);
   Expect.equals(1.1 * 1/3, 1/3 * 1.1);  // Test multiplication commutativity.
   Expect.equals(1.1.p * (1/3).p, (1/3).p * 1.1.p);
 
   print("Without chopping fractional bits:");
   Expect.isFalse(testAssociativity((x) => x));
   Expect.isFalse(testDistributivity((x) => x));
   print("With chopping fractional bits:");
   Expect.isTrue(testAssociativity((x) => x.p));
   Expect.isTrue(testDistributivity((x) => x.p));
 
   // Check that p works with NaN and Infinity.
   Expect.isTrue(double.NAN.p.isNaN);
   Expect.isTrue(double.INFINITY.p.isInfinite);
   Expect.isFalse(double.INFINITY.p.isNegative);
   Expect.isTrue(double.NEGATIVE_INFINITY.p.isInfinite);
   Expect.isTrue(double.NEGATIVE_INFINITY.p.isNegative);
 
   // Check use of assert to verify precision.
-  assertP(1.5);
-  assertP(1.1.p);
-  Expect.throws(() => assertP(1.1), (e) => e is AssertionError);
-  assertP(1.23456789.p);
-  Expect.throws(() => assertP(1.23456789), (e) => e is AssertionError);
+  if (assertionsEnabled()) {
+    assertP(1.5);
+    assertP(1.1.p);
+    Expect.throws(() => assertP(1.1), (e) => e is AssertionError);
+    assertP(1.23456789.p);
+    Expect.throws(() => assertP(1.23456789), (e) => e is AssertionError);
+  }
 }