Allow patch files to add top-level declarations to the patched library.

lib/compiler/implementation/ssa/codegen.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.
 
 class SsaCodeGeneratorTask extends CompilerTask {
   final JavaScriptBackend backend;
   SsaCodeGeneratorTask(JavaScriptBackend backend)
       : this.backend = backend,
         super(backend.compiler);
   String get name() => 'SSA code generator';
@@ skipping 17 matching lines @@
     // $.staticFun = function() {
     //   ...
     // };
     if (element.isInstanceMember() ||
         element.kind == ElementKind.GENERATIVE_CONSTRUCTOR_BODY) {
       extraSpace = " ";
     }
 
     String code = 'function($parameters) {\n$body$extraSpace}';
     List<SourceMappingEntry> sourceMappings = new List<SourceMappingEntry>();
-    SourceFile sourceFile = element.getCompilationUnit().script.file;
+    SourceFile sourceFile = element.getScript().file;
     FunctionExpression expression = element.cachedNode;
     sourceMappings.add(new SourceMappingEntry(
       sourceFile, expression.getBeginToken().charOffset, 0));
     sourceMappings.add(new SourceMappingEntry(
       sourceFile, expression.getEndToken().charOffset, code.length - 1));
     return new CodeBlock(code, sourceMappings);
   }
 
   CodeBlock generateMethod(WorkItem work, HGraph graph) {
     return measure(() {
@@ skipping 3062 matching lines @@
   if (leftType.canBeNull() && rightType.canBeNull()) {
     if (left.isConstantNull() || right.isConstantNull() ||
         (leftType.isPrimitive() && leftType == rightType)) {
       return '==';
     }
     return null;
   } else {
     return '===';
   }
 }