0537c9d326
DartType.subst would accidentally drop FunctionTypeVariables that had bounds modified by substitution. Use a visitor for printing, with changes that make it possible to see the accidentally free FunctionTypeVariables that were dropped. Change-Id: Ie6c8d0bb8f2a22b11db6f009067cf64e38ab93c7 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/113600 Commit-Queue: Stephen Adams <sra@google.com> Reviewed-by: Johnni Winther <johnniwinther@google.com>