Move Map to types to ensure it is visible in definition files

src/compiler/core.ts

@@ -15,10 +15,6 @@ module ts {
         True  = -1
     }
 
-    export interface Map<T> {
-        [index: string]: T;
-    }
-
     export const enum Comparison {
         LessThan    = -1,
         EqualTo     = 0,

src/compiler/types.ts

@@ -1,6 +1,9 @@
 /// <reference path="core.ts"/>
 
 module ts {
+    export interface Map<T> {
+        [index: string]: T;
+    }
 
     export interface TextRange {
         pos: number;