Make int an abstract class.

runtime/vm/object.h

Index: runtime/vm/object.h
diff --git a/runtime/vm/object.h b/runtime/vm/object.h
index 9bb6a1708ec56b5da0a6461033746074a1f348e6..6712b4a33e061a7ecd0524a13cdb0149c144bba4 100644
--- a/runtime/vm/object.h
+++ b/runtime/vm/object.h
@@ -875,8 +875,8 @@ class AbstractType : public Object {
   // Check if this type represents the 'bool' type.
   bool IsBoolType() const;
 
-  // Check if this type represents the 'int' interface.
-  bool IsIntInterface() const;
+  // Check if this type represents the 'int' type.
+  bool IsIntType() const;
 
   // Check if this type represents the 'double' type.
   bool IsDoubleType() const;
@@ -993,8 +993,8 @@ class Type : public AbstractType {
   // The 'bool' type.
   static RawType* BoolType();
 
-  // The 'int' interface type.
-  static RawType* IntInterface();
+  // The 'int' type.
+  static RawType* IntType();
 
   // The 'Smi' type.
   static RawType* SmiType();