universal function type RTTI is not working

[jmesserly]

from @vsmenon comment here: #27952 (comment)

The original example now gives a static error. If I change foo(h, 42) to foo(h as dynamic, 42), I do get a runtime error:

Type 'JSObject<makeGenericFnType>' is not a subtype of type '(Object) -> dynamic'

the repro is:

h/*<T>*/(a) {
  return a as dynamic/*=T*/;
}

Object foo(f(Object a), Object a) {
  return f(a);
}

void main() {
  var x = foo(h as dynamic, 42);
  print(x);
}

the type of h is showing up as JSObject<makeGenericFnType> but it should be <T>(dynamic) -> dynamic

[jmesserly]

node dcalls also do not work on these, likely for the same reason, see #28105

[jmesserly]

I will probably wait for this CL to land: https://codereview.chromium.org/2623053004/ as it changes a lot of function type tracking in DDC

[jmesserly]

I've got a test for this. Things seem to be working correctly in terms of dynamic calls. The main issue is we don't print the type in a reasonable way.

EDIT: also we don't implement subtype relation at all. Working on that.

[jmesserly]

This is basically fixed in d26bb56. I've got one more test I'm going to look at landing for it but otherwise we're good to go here.