This includes:
- An additional check in the format stdlib function to fail if there are
too many arguments given, rather than silently ignoring.
- Refinements for the type unification behavior to allow unification of
object/tuple types into weaker map/list types when no other unification
is possible.
- Improvements to the error messages for failed type conversions on
collection and structural types to talk about mismatching element types
where possible, rather than the outer value.
65c0826293