VM: Restore old implementation of ClassID.cid* fields

tools/patch_sdk.dart

 #!/usr/bin/env dart
 // Copyright (c) 2015, 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.
 
 /// Command line tool to merge the SDK libraries and our patch files.
 /// This is currently designed as an offline tool, but we could automate it.
 
 import 'dart:io';
 import 'dart:math' as math;
@@ skipping 239 matching lines @@
       if (!patchFinder.applied.contains(patched)) {
         print('*** ${patched}');
       }
     }
     throw "Failed to apply all @patch-es";
   }
 
   return new List<String>.from(results.map((e) => e.toString()));
 }
 
+final injectedCidFields = [
+  'Array', 'ExternalOneByteString', 'GrowableObjectArray',
+  'ImmutableArray', 'OneByteString', 'TwoByteString', 'Bigint'
+].map((name) => "static final int cid${name} = 0;").join('\n');
+
 /// Merge `@patch` declarations into `external` declarations.
 class PatchApplier extends GeneralizingAstVisitor {
   final StringEditBuffer edits;
   final PatchFinder patch;
 
   bool _isLibrary = true; // until proven otherwise.
 
   PatchApplier(this.edits, this.patch);
 
   @override
   visitCompilationUnit(CompilationUnit node) {
     super.visitCompilationUnit(node);
     if (_isLibrary) _mergeUnpatched(node);
   }
 
   void _merge(AstNode node, int pos) {
     var code = patch.contents.substring(node.offset, node.end);
+
+    // We inject a number of static fields into dart:internal.ClassID class.
+    // These fields represent various VM class ids and are only used to
+    // make core libraries compile. Kernel reader will actually ignore this
+    // fields and instead inject concrete constants into this class.
+    if (node is ClassDeclaration && node.name.name == 'ClassID') {
+      code = code.replaceFirst(
+          new RegExp(r'}$'), injectedCidFields + '}');
+    }
     edits.insert(pos, '\n' + code);
   }
 
   /// Merges directives and declarations that are not `@patch` into the library.
   void _mergeUnpatched(CompilationUnit unit) {
     // Merge imports from the patch
     // TODO(jmesserly): remove duplicate imports
 
     // To patch a library, we must have a library directive
     var libDir = unit.directives.first as LibraryDirective;
@@ skipping 233 matching lines @@
     if (diff != 0) return diff;
     return end - other.end;
   }
 }
 
 List<SdkLibrary> _getSdkLibraries(String contents) {
   var libraryBuilder = new SdkLibrariesReader_LibraryBuilder(true);
   parseCompilationUnit(contents).accept(libraryBuilder);
   return libraryBuilder.librariesMap.sdkLibraries;
 }