consisting of identifiers (C<Foo>), unions (C<... | ...>), and parametric types
(C<...[...]>). Example:
- fun foo(Int $n, ArrayRef[String | CodeRef] $cb) { ... }
+ fun foo(Int $n, ArrayRef[Str | CodeRef] $cb) { ... }
If you do this, the type reification function corresponding to the keyword will
be called to turn the type (a string) into a constraint object. The default