TestMLRandom: generate trivial annotations

This trivial annotation is useful to test the translation of
annotations from ML to System F: the annotation (t : some a. a) should
be elaborated into an annotation (t : ty) where (ty) is the inferred
type for (t).
1 job for !28 with F-annot in 8 minutes and 7 seconds (queued for 1 second)
latest detached
Status Job ID Name Coverage
  Build
passed #1194393
build: [4.12.0]

00:08:07