Function parameter type inference doesn't work with keyof of generic type

[user471]

TypeScript Version: 3.1.0-dev.201xxxxx

Search Terms:
function parameter type inference keyof generic
Code

function foo1<T>(foo: T, bar: {[key in keyof {foo: number}] : (x: T) => number }) {
}

function foo2<T>(foo: T, bar: {[key in keyof T] : (x: T) => number }) {
}

foo1({foo: 1}, {foo: x1 => x1.foo + 1})
foo2({foo: 1}, {foo: x2 => x2.foo + 1})

Expected behavior:
x2 has type {foo:number}
Actual behavior:
Compiler error
TS7006: Parameter 'x2' implicitly has an 'any' type.

x1 has type {foo:number}
but
x2 has type any

Playground Link:
Playground

[user471]

Is there any workaround?

[ahejlsberg]

This is fixed by #30568.