swift234

stdlib: rename mapping sequence and collection wrappers to a common naming convention

  // Renamed from `MapSequenceGenerator`.
  struct MapGenerator<Base : GeneratorType, Element> { ... }

  // Renamed from `MapSequenceView`.
  struct MapSequence<Base : SequenceType, Element> { ... }

  // Renamed from `MapCollectionView`.
  struct MapCollection<Base : CollectionType, Element> { ... }

Part of rdar://21429126

Swift SVN r29632