Context queries: Ambiguity between given argument and call to apply()

Given a function definition
```
def foo = given (v: Int) => (x: Int) => v + x
implied myInt for Int = 4
```
Both ```foo.apply(7)``` and ```(foo given 4)(7)``` works fine, but ```foo(7)``` fails to compile (method apply in trait ImplicitFunction1 does not take more parameters).

Tested with Dotty 0.13.0-RC1 and 0.14.0-bin-20190220-60c4bf8-NIGHTLY.