Revert hiding of VM-only coreimpl list implementation types. While I

runtime/bin/common.dart

Index: runtime/bin/common.dart
diff --git a/runtime/bin/common.dart b/runtime/bin/common.dart
index fafd02ac7176a737be8968235e65c15a770bbc8b..614171c440ca40d1d0f69543879b6ba15b57ef28 100644
--- a/runtime/bin/common.dart
+++ b/runtime/bin/common.dart
@@ -7,13 +7,10 @@
   * operating system.
   */
 class OSError {
-  /** Constant used to indicate that no OS error code is available. */
   static const int noErrorCode = -1;
 
-  /** Creates an OSError object from a message and an errorCode. */
   const OSError([String this.message = "", int this.errorCode = noErrorCode]);
 
-  /** Converts an OSError object to a string representation. */
   String toString() {
     StringBuffer sb = new StringBuffer();
     sb.add("OS Error");
@@ -43,40 +40,3 @@ class OSError {
     */
   final int errorCode;
 }
-
-
-// Check if a List is a builtin VM List type. Returns true
-// if the List is a builtin VM List type and false if it is
-// a user defined List type.
-//
-// TODO(5474): At this point it actually return false for
-// _GrowableObjectArrays because of serialization issues.
-bool _isBuiltinList(List buffer) native "Common_IsBuiltinList";
-
-
-// Ensure that the input List can be serialized through a native port.
-// Only builtin Lists can be serialized through. If user-defined Lists
-// get here, the contents is copied to a Uint8List. This has the added
-// benefit that it is faster to access from the C code as well.
-List _ensureFastAndSerializableBuffer(
-    List buffer, int offset, int bytes) {
-  List outBuffer;
-  int outOffset = offset;
-  if (buffer is Uint8List || _isBuiltinList(buffer)) {
-    outBuffer = buffer;
-  } else {
-    outBuffer = new Uint8List(bytes);
-    outOffset = 0;
-    int j = offset;
-    for (int i = 0; i < bytes; i++) {
-      int value = buffer[j];
-      if (value is! int) {
-        throw new FileIOException(
-            "List element is not an integer at index $j");
-      }
-      outBuffer[i] = value;
-      j++;
-    }
-  }
-  return [outBuffer, outOffset];
-}