Move DateImplementation from coreimpl to core, making it private.

lib/compiler/implementation/lib/coreimpl_patch.dart

Index: lib/compiler/implementation/lib/coreimpl_patch.dart
diff --git a/lib/compiler/implementation/lib/coreimpl_patch.dart b/lib/compiler/implementation/lib/coreimpl_patch.dart
index 9b6306416a565405394216416ce707b75dbb416c..d2a638d4ec982e9ab07b8336c7b118d7f6e1b903 100644
--- a/lib/compiler/implementation/lib/coreimpl_patch.dart
+++ b/lib/compiler/implementation/lib/coreimpl_patch.dart
@@ -69,65 +69,6 @@ patch class ListImplementation<E> {
 }
 
 
-// Patch for Date implementation.
-// TODO(ager): Split out into date_patch.dart and allow #source
-// in patch files?
-patch class DateImplementation {
-  patch DateImplementation(int year,
-                           int month,
-                           int day,
-                           int hour,
-                           int minute,
-                           int second,
-                           int millisecond,
-                           bool isUtc)
-      : this.isUtc = checkNull(isUtc),
-        millisecondsSinceEpoch = Primitives.valueFromDecomposedDate(
-            year, month, day, hour, minute, second, millisecond, isUtc) {
-    Primitives.lazyAsJsDate(this);
-  }
-
-  patch DateImplementation.now()
-      : isUtc = false,
-        millisecondsSinceEpoch = Primitives.dateNow() {
-    Primitives.lazyAsJsDate(this);
-  }
-
-  patch static int _brokenDownDateToMillisecondsSinceEpoch(
-      int year, int month, int day, int hour, int minute, int second,
-      int millisecond, bool isUtc) {
-    return Primitives.valueFromDecomposedDate(
-        year, month, day, hour, minute, second, millisecond, isUtc);
-  }
-
-  patch String get timeZoneName {
-    if (isUtc) return "UTC";
-    return Primitives.getTimeZoneName(this);
-  }
-
-  patch Duration get timeZoneOffset {
-    if (isUtc) return new Duration();
-    return new Duration(minutes: Primitives.getTimeZoneOffsetInMinutes(this));
-  }
-
-  patch int get year => Primitives.getYear(this);
-
-  patch int get month => Primitives.getMonth(this);
-
-  patch int get day => Primitives.getDay(this);
-
-  patch int get hour => Primitives.getHours(this);
-
-  patch int get minute => Primitives.getMinutes(this);
-
-  patch int get second => Primitives.getSeconds(this);
-
-  patch int get millisecond => Primitives.getMilliseconds(this);
-
-  patch int get weekday => Primitives.getWeekday(this);
-}
-
-
 // Patch for Stopwatch implementation.
 // TODO(ager): Split out into stopwatch_patch.dart and allow #source
 // in patch files?