Revert "Move dart2js from sdk/lib/_internal/compiler to pkg/compiler"

pkg/compiler_unsupported/tool/create_library.py

 #!/usr/bin/env python
 #
 # Copyright (c) 2014, 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.
 #
 # Create the compiler_unsupported package. This will copy the
 # sdk/lib/_internal/compiler directory and the libraries.dart file into lib/.
 #
 # Usage: create_library.py
@@ skipping 26 matching lines @@
 def Main(argv):
   # pkg/compiler_unsupported
   HOME = dirname(dirname(os.path.realpath(__file__)))
 
   # pkg/compiler_unsupported/lib
   TARGET = join(HOME, 'lib')
 
   # sdk/lib/_internal
   SOURCE = join(dirname(dirname(HOME)), 'sdk', 'lib', '_internal')
 
-  # pkg
-  PKG_SOURCE = join(dirname(dirname(HOME)), 'pkg')
-
   # clean compiler_unsupported/lib
   if not os.path.exists(TARGET):
     os.mkdir(TARGET)
-  shutil.rmtree(join(TARGET, 'src'), True)
+  shutil.rmtree(join(TARGET, 'implementation'), True)
   RemoveFile(join(TARGET, 'compiler.dart'))
   RemoveFile(join(TARGET, 'libraries.dart'))
 
   # copy dart2js code
-  shutil.copy(join(PKG_SOURCE, 'compiler', 'lib', 'compiler.dart'), TARGET)
+  shutil.copy(join(SOURCE, 'compiler', 'compiler.dart'), TARGET)
   shutil.copy(join(SOURCE, 'libraries.dart'), TARGET)
   shutil.copytree(
-      join(PKG_SOURCE, 'compiler', 'lib', 'src'),
-      join(TARGET, 'src'))
+      join(SOURCE, 'compiler', 'implementation'),
+      join(TARGET, 'implementation'))
 
   # patch up the libraries.dart references
   replace = [(r'\.\./\.\./libraries\.dart', r'\.\./libraries\.dart')]
 
-  for root, dirs, files in os.walk(join(TARGET, 'src')):
+  for root, dirs, files in os.walk(join(TARGET, 'implementation')):
     for name in files:
       if name.endswith('.dart'):
         ReplaceInFiles([join(root, name)], replace)
 
 
 if __name__ == '__main__':
   sys.exit(Main(sys.argv))