Cannot use otherwise bound names as type variables

[Stephen Chang]

example:

#lang mlish

(define-type (Test X)
  (A X))

(define (f [x : (Test A)] -> (Test A)) 
  x)

Rather than using the A in f's signature as a type variable, it thinks it refers to the A constructor and produces the error:

; TYPE-ERROR: tmp.mlish (6:22): constructor A must instantiate 1 type argument(s): X
; and be applied to 1 arguments with type(s): X

There may not be anything I can do about this, unless type variables are further distinguished somehow.

[Stephen Chang]

infer quantified type variables in the order that they occur (L-to-R)

• backwards incompatible change: quantified type variables no longer sorted lex
• fix and add tests, remove some annotations in tests
• small speed improvement due to eliminating some extra expansions
• closes #9, closes #11

→ <<cset c64251cac0e8>>