src/vs/code/electron-main/main.ts/CodeMain/patchEnvironment
class CodeMain:	private patchEnvironment(environmentMainService: IEnvironmentMainService): IProcessEnvironment {
		const instanceEnvironment: IProcessEnvironment = {
			VSCODE_IPC_HOOK: environmentMainService.mainIPCHandle
		};

		['VSCODE_NLS_CONFIG', 'VSCODE_PORTABLE'].forEach(key => {
			const value = process.env[key];
			if (typeof value === 'string') {
				instanceEnvironment[key] = value;
			}
		});

		Object.assign(process.env, instanceEnvironment);

		return instanceEnvironment;
	}