support instantiated tear-offs

[jmesserly]

Initial implementation of #301 may not cover this.

• identify these nodes in the AST by examining the staticType
• emit the instantiation
• ensure RTTI is associated

The nodes this can happen to are: PropertyAccess, PrefixedIdentifier and SimpleIdentifier.

You can't write the instantiation explicitly yet (o.m<String>) but it can be inferred by the type system. These do come up in practice, so we shouldn't defer this one too long. For example, passing a generic function to something that expects a non-generic function type.

[jmesserly]

Now that the CL is out for #301, I will take a look at this one

[jmesserly]

Here's an example:

import 'dart:math' show min; // <-- generic: <T extends num>(T, T) -> T
typedef int Int2Int2Int(int x, int y);
main() {
  Int2Int2Int f = min; // Strong mode infers: `min<int>`
  int y = f(123, 456); // should work in DDC
  (f as dynamic)/*<int>*/(123, 456); // runtime error: can't pass type args, `f` doesn't take type args
  (min as dynamic)/*<int>*/(123, 456); // this should work: dynamic call with type args
  (min as dynamic)(123, 456); // this too
  print(y);
}

[jmesserly]

https://codereview.chromium.org/1930323004/