Using .call on a known function type should not be a dynamic call

[leafpetersen]

This code:

void f(int x) => print(x);
void main() {
  f.call("hello");
}

gets no errors or warnings in strong mode. Since we know the type of f, which should treat this as a regular call, and issue an error.

[jmesserly]

P1 because I think this is blocking someone?

[jmesserly]

Marking P2 ... Leaf has a workaround from the DDC side :)

[jmesserly]

https://codereview.chromium.org/2226903003