issue 4817 fixed. Implemented raw strings with 'r' instead of '@' for dart2js

tests/compiler/dart2js/resolver_test.dart

 // Copyright (c) 2012, 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.
 
 #import('dart:uri');
 
 #import("../../../lib/compiler/implementation/leg.dart");
 #import("../../../lib/compiler/implementation/elements/elements.dart");
 #import("../../../lib/compiler/implementation/tree/tree.dart");
 #import("../../../lib/compiler/implementation/scanner/scannerlib.dart");
@@ skipping 645 matching lines @@
                 A() : foo();
               }""";
   resolveConstructor(script, "A a = new A();", "A", "A", 0,
                      [], [MessageKind.CONSTRUCTOR_CALL_EXPECTED]);
 
   script = """class A {
                 int i;
                 A.a() : this.b(0);
                 A.b(int i);
               }""";
-  resolveConstructor(script, "A a = new A.a();", "A", @"A$a", 1,
+  resolveConstructor(script, "A a = new A.a();", "A", r"A$a", 1,
                      [], []);
 
   script = """class A {
                 int i;
                 A.a() : i = 42, this(0);
                 A(int i);
               }""";
-  resolveConstructor(script, "A a = new A.a();", "A", @"A$a", 2,
+  resolveConstructor(script, "A a = new A.a();", "A", r"A$a", 2,
                      [], [MessageKind.REDIRECTING_CONSTRUCTOR_HAS_INITIALIZER]);
 
   script = """class A {
                 int i;
                 A(i);
               }
               class B extends A {
                 B() : super(0);
               }""";
   resolveConstructor(script, "B a = new B();", "B", "B", 1,
@@ skipping 51 matching lines @@
 
 checkMemberResolved(compiler, className, memberName) {
   Element memberElement = findElement(compiler, className)
       .lookupLocalMember(memberName);
   Expect.isNotNull(memberElement);
   Expect.isNotNull(
       compiler.enqueuer.resolution.getCachedElements(memberElement));
 }
 
 testToString() {
-  final script = @"class C { toString() => 'C'; } main() { '${new C()}'; }";
+  final script = r"class C { toString() => 'C'; } main() { '${new C()}'; }";
   final compiler = compileScript(script);
 
   checkMemberResolved(compiler, 'C', buildSourceString('toString'));
 }
 
 operatorName(op, isUnary) {
   return Elements.constructOperatorName(new SourceString(op), isUnary);
 }
 
 testIndexedOperator() {
-  final script = @"""
+  final script = r"""
       class C {
         operator[](ix) => ix;
         operator[]=(ix, v) {}
       }
       main() { var c = new C(); c[0]++; }""";
   final compiler = compileScript(script);
 
   checkMemberResolved(compiler, 'C', operatorName('[]', false));
   checkMemberResolved(compiler, 'C', operatorName('[]=', false));
 }
 
 testIncrementsAndDecrements() {
-  final script = @"""
+  final script = r"""
       class A { operator+(o)=>null; }
       class B { operator+(o)=>null; }
       class C { operator-(o)=>null; }
       class D { operator-(o)=>null; }
       main() {
         var a = new A();
         a++;
         var b = new B();
         ++b;
         var c = new C();
         c--;
         var d = new D();
         --d;
       }""";
   final compiler = compileScript(script);
 
   checkMemberResolved(compiler, 'A', operatorName('+', false));
   checkMemberResolved(compiler, 'B', operatorName('+', false));
   checkMemberResolved(compiler, 'C', operatorName('-', false));
   checkMemberResolved(compiler, 'D', operatorName('-', false));
 }