Remove generated directories with 100s of files.

client/dom/generated/src/frog/Uint8ClampedArray.dart

-
-class _Uint8ClampedArrayJs extends _Uint8ArrayJs implements Uint8ClampedArray, List<int> native "*Uint8ClampedArray" {
-
-  factory Uint8ClampedArray(int length) =>  _construct_Uint8ClampedArray(length);
-
-  factory Uint8ClampedArray.fromList(List<int> list) => _construct_Uint8ClampedArray(list);
-
-  factory Uint8ClampedArray.fromBuffer(ArrayBuffer buffer) => _construct_Uint8ClampedArray(buffer);
-
-  static _construct_Uint8ClampedArray(arg) native 'return new Uint8ClampedArray(arg);';
-
-  // Use implementation from Uint8Array.
-  // final int length;
-
-  void setElements(Object array, [int offset = null]) native '''
-if (offset == null) return this.set(array);
-return this.set(array, offset);''';
-
-  _Uint8ClampedArrayJs subarray(int start, [int end = null]) native;
-}