Move frog/leg to lib/compiler/implementation.

frog/leg/leg.dart

-// Copyright (c) 2011, 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.
-
-#library('leg');
-
-#import('../../lib/uri/uri.dart');
-
-#import('colors.dart');
-#import('elements/elements.dart');
-#import('native_handler.dart', prefix: 'native');
-#import('scanner/scanner_implementation.dart');
-#import('scanner/scannerlib.dart');
-#import('ssa/ssa.dart');
-#import('string_validator.dart');
-#import('tree/tree.dart');
-#import('util/characters.dart');
-#import('util/util.dart');
-
-#source('compile_time_constants.dart');
-#source('compiler.dart');
-#source('diagnostic_listener.dart');
-#source('emitter.dart');
-#source('enqueue.dart');
-#source('namer.dart');
-#source('native_emitter.dart');
-#source('operations.dart');
-#source('resolver.dart');
-#source('script.dart');
-#source('tree_validator.dart');
-#source('typechecker.dart');
-#source('universe.dart');
-#source('warnings.dart');
-
-void unreachable() {
-  throw const Exception("Internal Error (Leg): UNREACHABLE");
-}