am 556c60f4: am 51da51a2: am 02effee6: Correctly compute the type of an assignment expression.

Merge commit '556c60f4f27e2a3bfde6a47acf876716ea8d5795'

* commit '556c60f4f27e2a3bfde6a47acf876716ea8d5795':
  Correctly compute the type of an assignment expression.