[cfe] Does not apply call insertion in pattern declaration

[eernstg]

Consider the following program:

class A {
  X call<X>(X x) => x;
}

void g(A a) {
  var Function(call: f) = a;
  Function g = a; // This works.
}

The CFE (SDK 3.0.0-322.0.dev) reports a compile-time error for this program:

Error: The matched value of type 'A' isn't assignable to the required type 'Function'.
 - 'A' is from 'package:dartpad_sample/main.dart' ('lib/main.dart').
 - 'Function' is from 'dart:core'.
  var Function(call: f) = a;
      ^

However, I would expect this situation to give rise to a 'call insertion' coercion, that is, the initializing expression should have been transformed from a into a.call, based on the context type Function.

[sgrekhov]

The following two co19 tests fails because of this issue

https://github.com/dart-lang/co19/blob/master/LanguageFeatures/Patterns/type_inference_A13_t04.dart
https://github.com/dart-lang/co19/blob/master/LanguageFeatures/Patterns/type_inference_A14_t04.dart

[nshahan]

cc @johnniwinther

I believe there is a related test failure because of a missing call method tearoff coercion in

language/patterns/call_tear_off_test