Eliminate unary plus with hex literals

tests/corelib/math_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.
 
 class MathTest {
   static void testConstants() {
     // Source for mathematical constants is Wolfram Alpha.
     Expect.equals(2.7182818284590452353602874713526624977572470936999595749669,
                   Math.E);
     Expect.equals(2.3025850929940456840179914546843642076011014886287729760333,
@@ skipping 153 matching lines @@
     Expect.equals(499, Math.parseInt("   499   "));
     Expect.equals(499, Math.parseInt("   +499   "));
     Expect.equals(-499, Math.parseInt("   -499   "));
     Expect.equals(0, Math.parseInt("0"));
     Expect.equals(0, Math.parseInt("+0"));
     Expect.equals(0, Math.parseInt("-0"));
     Expect.equals(0, Math.parseInt("   0   "));
     Expect.equals(0, Math.parseInt("   +0   "));
     Expect.equals(0, Math.parseInt("   -0   "));
     Expect.equals(0x1234567890, Math.parseInt("0x1234567890"));
-    Expect.equals(0x1234567890, Math.parseInt("+0x1234567890"));
     Expect.equals(-0x1234567890, Math.parseInt("-0x1234567890"));
     Expect.equals(0x1234567890, Math.parseInt("   0x1234567890   "));
-    Expect.equals(0x1234567890, Math.parseInt("   +0x1234567890   "));
     Expect.equals(-0x1234567890, Math.parseInt("   -0x1234567890   "));
     Expect.equals(256, Math.parseInt("0x100"));
-    Expect.equals(256, Math.parseInt("+0x100"));
     Expect.equals(-256, Math.parseInt("-0x100"));
     Expect.equals(256, Math.parseInt("   0x100   "));
-    Expect.equals(256, Math.parseInt("   +0x100   "));
     Expect.equals(-256, Math.parseInt("   -0x100   "));
     Expect.equals(0xabcdef, Math.parseInt("0xabcdef"));
     Expect.equals(0xABCDEF, Math.parseInt("0xABCDEF"));
     Expect.equals(0xabcdef, Math.parseInt("0xabCDEf"));
     Expect.equals(-0xabcdef, Math.parseInt("-0xabcdef"));
     Expect.equals(-0xABCDEF, Math.parseInt("-0xABCDEF"));
     Expect.equals(0xabcdef, Math.parseInt("   0xabcdef   "));
     Expect.equals(0xABCDEF, Math.parseInt("   0xABCDEF   "));
     Expect.equals(-0xabcdef, Math.parseInt("   -0xabcdef   "));
     Expect.equals(-0xABCDEF, Math.parseInt("   -0xABCDEF   "));
@@ skipping 32 matching lines @@
     Expect.equals(true, parseIntThrowsBadNumberFormatException("0x3.1"));
     Expect.equals(true, parseIntThrowsBadNumberFormatException("5."));
     Expect.equals(true, parseIntThrowsBadNumberFormatException("+-5"));
     Expect.equals(true, parseIntThrowsBadNumberFormatException("-+5"));
     Expect.equals(true, parseIntThrowsBadNumberFormatException("--5"));
     Expect.equals(true, parseIntThrowsBadNumberFormatException("++5"));
     Expect.equals(true, parseIntThrowsBadNumberFormatException("+ 5"));
     Expect.equals(true, parseIntThrowsBadNumberFormatException("- 5"));
     Expect.equals(true, parseIntThrowsBadNumberFormatException(""));
     Expect.equals(true, parseIntThrowsBadNumberFormatException("  "));
+    Expect.equals(true, parseIntThrowsBadNumberFormatException("+0x1234567890"));
+    Expect.equals(true, parseIntThrowsBadNumberFormatException("   +0x1234567890   "));
+    Expect.equals(true, parseIntThrowsBadNumberFormatException("+0x100"));
+    Expect.equals(true, parseIntThrowsBadNumberFormatException("   +0x100   "));
   }
 
   static testMain() {
     testConstants();
     testSin();
     testCos();
     testTan();
     testAsin();
     testAcos();
     testAtan();
     testAtan2();
     testSqrt();
     testLog();
     testExp();
     testPow();
     testParseInt();
   }
 }
 
 main() {
   MathTest.testMain();
 }