Fixing new compile error detected by 2.0 compiler

src/vs/base/parts/ipc/common/ipc.ts

@@ -59,7 +59,7 @@ enum State {
 }
 
 export interface IChannel {
-	call(command: string, arg: any): TPromise<any>;
+	call(command: string, arg?: any): TPromise<any>;
 }
 
 export interface IChannelServer {

src/vs/code/common/windowsIpc.ts

@@ -13,7 +13,7 @@ import Event, { buffer } from 'vs/base/common/event';
 export interface IWindowsChannel extends IChannel {
 	call(command: 'event:onNewWindowOpen'): TPromise<number>;
 	call(command: 'event:onWindowFocus'): TPromise<number>;
-	call(command: string, arg: any): any;
+	call(command: string, arg?: any): any;
 }
 
 export class WindowsChannel implements IWindowsChannel {
@@ -26,7 +26,7 @@ export class WindowsChannel implements IWindowsChannel {
 		this.onWindowFocus = buffer(service.onWindowFocus, true);
 	}
 
-	call(command: string, args: any): any {
+	call(command: string, args?: any): any {
 		switch (command) {
 			case 'event:onNewWindowOpen':
 				return eventToCall(this.onNewWindowOpen);

src/vs/platform/message/common/messageIpc.ts

@@ -11,7 +11,7 @@ import { IChoiceService, Severity } from 'vs/platform/message/common/message';
 
 export interface IChoiceChannel extends IChannel {
 	call(command: 'choose'): TPromise<number>;
-	call(command: string, arg: any): TPromise<any>;
+	call(command: string, arg?: any): TPromise<any>;
 }
 
 export class ChoiceChannel implements IChoiceChannel {
@@ -19,7 +19,7 @@ export class ChoiceChannel implements IChoiceChannel {
 	constructor(private service: IChoiceService) {
 	}
 
-	call(command: string, args: any): TPromise<any> {
+	call(command: string, args?: any): TPromise<any> {
 		switch (command) {
 			case 'choose': return this.service.choose(<Severity>args[0], <string>args[1], <string[]>args[2]);
 		}

src/vs/workbench/parts/debug/node/debugAdapter.ts

@@ -80,7 +80,7 @@ export class Adapter {
 		this.aiKey = rawAdapter.aiKey;
 	}
 
-	public getInitialConfigurations(): TPromise<string> {
+	public getInitialConfigurations(): TPromise<string | any[]> {
 		if (typeof this.initialConfigurations === 'string') {
 			// Contributed initialConfigurations is a command that needs to be invoked
 			// Debug adapter will dynamically provide the initial conifguraiton