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

lib/compiler/implementation/scanner/listener.dart

Index: lib/compiler/implementation/scanner/listener.dart
diff --git a/lib/compiler/implementation/scanner/listener.dart b/lib/compiler/implementation/scanner/listener.dart
index 0963033e335cdf0e755da3b1e5acce2ec2aa95fe..7d18d4d8ed3ea36f354eb1bb7fb119a0ae8c23ac 100644
--- a/lib/compiler/implementation/scanner/listener.dart
+++ b/lib/compiler/implementation/scanner/listener.dart
@@ -1514,17 +1514,6 @@ class PartialFunctionElement extends FunctionElement {
     if (patch !== null) return patch.position();
     return findMyName(beginToken);
   }
-
-  PartialFunctionElement cloneTo(Element enclosing,
-                                 DiagnosticListener listener) {
-    if (patch !== null) {
-      listener.cancel("Cloning a patched function.", element: this);
-    }
-    PartialFunctionElement result = new PartialFunctionElement(
-        name, beginToken, getOrSet, endToken, kind, modifiers, enclosing);
-    result.scriptOverride = getScript();
-    return result;
-  }
 }
 
 class PartialFieldListElement extends VariableListElement {
@@ -1554,14 +1543,6 @@ class PartialFieldListElement extends VariableListElement {
   }
 
   Token position() => beginToken; // findMyName doesn't work. I'm nameless.
-
-  PartialFieldListElement cloneTo(Element enclosing,
-                                  DiagnosticListener listener) {
-    PartialFieldListElement result = new PartialFieldListElement(
-        beginToken, endToken, modifiers, enclosing);
-    result.scriptOverride = getScript();
-    return result;
-  }
 }
 
 class PartialTypedefElement extends TypedefElement {
@@ -1579,14 +1560,6 @@ class PartialTypedefElement extends TypedefElement {
   }
 
   position() => findMyName(token);
-
-  PartialTypedefElement cloneTo(Element enclosing,
-                                DiagnosticListener listener) {
-    PartialTypedefElement result =
-        new PartialTypedefElement(name, enclosing, token);
-    result.scriptOverride = getScript();
-    return result;
-  }
 }
 
 Node parse(DiagnosticListener diagnosticListener,