- Move double and int implementations into dart:core and make them private.

lib/integers.dart

Index: lib/integers.dart
===================================================================
--- lib/integers.dart	(revision 12304)
+++ lib/integers.dart	(working copy)
@@ -4,10 +4,10 @@
 
 // TODO(srdjan): fix limitations.
 // - shift amount must be a Smi.
-class IntegerImplementation {
-  factory IntegerImplementation._uninstantiable() {
+class _IntegerImplementation {
+  factory _IntegerImplementation._uninstantiable() {
     throw const UnsupportedOperationException(
-        "IntegerImplementation can only be allocated by the VM");
+        "_IntegerImplementation can only be allocated by the VM");
   }
   num operator +(num other) {
     return other.addFromInteger(this);
@@ -132,13 +132,13 @@
   int truncate() { return this; }
 
   int toInt() { return this; }
-  double toDouble() { return new Double.fromInteger(this); }
+  double toDouble() { return new _Double.fromInteger(this); }
 
   int pow(int exponent) {
     double res = this.toDouble().pow(exponent);
     if (res.isInfinite()) {
       // Use Bigint instead.
-      throw "IntegerImplementation.pow not implemented for large integers.";
+      throw "_IntegerImplementation.pow not implemented for large integers.";
     }
     return res.toInt();
   }
@@ -178,10 +178,10 @@
   }
 }
 
-class Smi extends IntegerImplementation implements int {
-  factory Smi._uninstantiable() {
+class _Smi extends _IntegerImplementation implements int {
+  factory _Smi._uninstantiable() {
     throw const UnsupportedOperationException(
-        "Smi can only be allocated by the VM");
+        "_Smi can only be allocated by the VM");
   }
   int hashCode() {
     return this;
@@ -192,10 +192,10 @@
 }
 
 // Represents integers that cannot be represented by Smi but fit into 64bits.
-class Mint extends IntegerImplementation implements int {
-  factory Mint._uninstantiable() {
+class _Mint extends _IntegerImplementation implements int {
+  factory _Mint._uninstantiable() {
     throw const UnsupportedOperationException(
-        "Mint can only be allocated by the VM");
+        "_Mint can only be allocated by the VM");
   }
   int hashCode() {
     return this;
@@ -217,10 +217,10 @@
 
 // A number that can be represented as Smi or Mint will never be represented as
 // Bigint.
-class Bigint extends IntegerImplementation implements int {
-  factory Bigint._uninstantiable() {
+class _Bigint extends _IntegerImplementation implements int {
+  factory _Bigint._uninstantiable() {
     throw const UnsupportedOperationException(
-        "Bigint can only be allocated by the VM");
+        "_Bigint can only be allocated by the VM");
   }
   int hashCode() {
     return this;