Previously, it was possible that type arguments of recursive types are
shared between unrelated recursive types if they have exactly the same shape
(e.g. Foo extends Base<Foo> and Bar extends Base<Bar> both have
type arguments <recursive-ref#0>).
Fixes ffi/structs_test in AOT+bytecode mode.
Change-Id: I516bc34c3b5797d76e1bf087ac3c8f075f1b6424
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/120380
Reviewed-by: Régis Crelier <regis@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>