Named arguments type errors not formatted in some cases.

[jordwalke]

# Unformatted Error Output:
# File "product/virtual/team/validation/entity/SomeEntity.re", line 118, characters 23-28:
# Error: This expression has type
#          ?field:MyError.field ->
#          ?path:MyError.path -> ErrorCode.t -> Comp.unit
#        but an expression was expected of type
#          Validators.errorType =
#            ?blo:MyErrorsBLOStrings.t ->
#            ?helpID:MyTypes.id ->
#            ?title:Comp.string ->
#            ?field:MyError.field ->
#            ?path:MyError.path -> ErrorCode.t -> Comp.unit