Invalid reformatting of first-class module type with constraints

[jguyon]

Given this valid code:

module type Test = {type a;};
type t('a) = (module Test with type a = 'a);

Refmt prints this code which produces a syntax error:

module type Test = {type a;};
type t('a) = (module Test) with type a = 'a;

[anmonteiro]

Thanks for reporting.

This was a regression from #2124. Just opened #2151 with a fix.