tests/cases/conformance/async/es6/noCustomAsyncReturnType_es6.ts(3,5): error TS2529: Duplicate identifier 'Promise'. Compiler reserves name 'Promise' in top level scope of a module containing async functions.
tests/cases/conformance/async/es6/noCustomAsyncReturnType_es6.ts(5,28): error TS1064: The return type of an async function or method must be the global Promise<T> type.


==== tests/cases/conformance/async/es6/noCustomAsyncReturnType_es6.ts (2 errors) ====
    
    interface Promise<T> extends PromiseLike<T> {}
    var Promise: PromiseConstructorLike;
        ~~~~~~~
!!! error TS2529: Duplicate identifier 'Promise'. Compiler reserves name 'Promise' in top level scope of a module containing async functions.
    
    export async function f(): Promise<void> {
                               ~~~~~~~~~~~~~
!!! error TS1064: The return type of an async function or method must be the global Promise<T> type.
    }
    