Adding test and fix

src/services/refactors/moveToNewFile.ts

@@ -176,7 +176,7 @@ function getNewFileImportsAndAddExportInOldFile(
             if (hasSyntacticModifier(decl, ModifierFlags.Default)) {
                 oldFileDefault = name;
             }
-            else {
+            else if (!oldFileNamedImports.includes (name.text)) {
                 oldFileNamedImports.push(name.text);
             }
         }

tests/cases/fourslash/moveToNewFile_overloads5.ts

@@ -0,0 +1,36 @@
+/// <reference path='fourslash.ts' />
+
+// @Filename: /a.ts
+//// [|export function add(a: number, b: number): number;
+//// export function add(a: string, b: string): string;
+//// export function add(a: any, b: any): any {
+////     multiply(2,3);
+////   return a + b;
+//// }|]
+//
+//// function multiply(x: number, y: number): number;
+//// function multiply(x: string, y: string): string;
+//// function multiply(x: any, y: any) {
+////    return x + y;
+//// }
+
+verify.moveToNewFile({
+    newFileContents: {
+        "/a.ts":
+         `export function multiply(x: number, y: number): number;
+export function multiply(x: string, y: string): string;
+export function multiply(x: any, y: any) {
+   return x + y;
+}`,
+        "/add.ts":
+`import { multiply } from "./a";
+
+export function add(a: number, b: number): number;
+export function add(a: string, b: string): string;
+export function add(a: any, b: any): any {
+    multiply(2, 3);
+    return a + b;
+}
+`
+    },
+});