Exception while checking async function with unknown return type when noImplicitReturns

[texastoland]

TypeScript Version:

nightly (1.9.0-dev.20160622-1.0)

Code

// @noImplicitReturns: true
async () => { if (window) return }

Problem:

TypeError: Cannot read property 'flags' of undefined TypeError: Cannot read property 'flags' of undefined
    at maybeTypeOfKind (./node_modules/typescript/lib/typescript.js:27268:21)
    at isUnwrappedReturnTypeVoidOrAny (./node_modules/typescript/lib/typescript.js:29872:20)
    at checkAllCodePathsInNonVoidFunctionReturnOrThrow (./node_modules/typescript/lib/typescript.js:27027:25)
    at checkFunctionExpressionOrObjectLiteralMethodDeferred (./node_modules/typescript/lib/typescript.js:27091:17)
    at checkDeferredNodes (./node_modules/typescript/lib/typescript.js:31261:25)
    at checkSourceFileWorker (./node_modules/typescript/lib/typescript.js:31293:17)
    at checkSourceFile (./node_modules/typescript/lib/typescript.js:31275:13)
    at Object.forEach (./node_modules/typescript/lib/typescript.js:972:30)
    at getDiagnosticsWorker (./node_modules/typescript/lib/typescript.js:31323:16)
    at getDiagnostics (./node_modules/typescript/lib/typescript.js:31311:24)
    at Object.getEmitResolver (./node_modules/typescript/lib/typescript.js:16377:13)
    at emitWorker (./node_modules/typescript/lib/typescript.js:43812:69)
    at ./node_modules/typescript/lib/typescript.js:43777:66
    at runWithCancellationToken (./node_modules/typescript/lib/typescript.js:43858:24)
    at Object.emit (./node_modules/typescript/lib/typescript.js:43777:20)
    at Object.transpileModule (./node_modules/typescript/lib/typescript.js:52691:17)

CC @spicydonuts