Make LibraryMirror.members an internal native and lazy.

runtime/vm/raw_object.h

Index: runtime/vm/raw_object.h
===================================================================
--- runtime/vm/raw_object.h	(revision 25450)
+++ runtime/vm/raw_object.h	(working copy)
@@ -401,6 +401,7 @@
   static bool IsTypedDataClassId(intptr_t index);
   static bool IsTypedDataViewClassId(intptr_t index);
   static bool IsExternalTypedDataClassId(intptr_t index);
+  static bool IsImplementationClassId(intptr_t index);
 
   static intptr_t NumberOfTypedDataClasses();
 
@@ -1627,7 +1628,7 @@
   // Make sure this function is updated when new builtin List types are added.
   ASSERT(kImmutableArrayCid == kArrayCid + 1 &&
          kTypedDataCid == kGrowableObjectArrayCid + 1);
-  return ((index >= kArrayCid && index < kImmutableArrayCid) ||
+  return ((index >= kArrayCid && index <= kImmutableArrayCid) ||
           (index >= kGrowableObjectArrayCid && index < kTypedDataCid) ||
           IsTypedDataClassId(index) ||
           IsTypedDataViewClassId(index) ||
@@ -1704,6 +1705,13 @@
 }
 
 
+inline bool RawObject::IsImplementationClassId(intptr_t index) {
+  return IsBuiltinListClassId(index) ||
+      IsStringClassId(index) ||
+      IsNumberClassId(index);
+}
+
+
 inline intptr_t RawObject::NumberOfTypedDataClasses() {
   // Make sure this is updated when new TypedData types are added.
   ASSERT(kTypedDataInt8ArrayViewCid == kTypedDataInt8ArrayCid + 12);