Necessary to resolve any type arguments in a ref to a parameterized
iface. This meant that, for example:
class A implements B<int> { ...
didn't work before, because the "int" in B's argument wasn't getting
visited, and thus wasn't getting resolved. Now it works.
Partially addresses Issue #2288, but I also want to check that class
ty params can appear as the type arguments to ifaces (for example,
class A<T> implements B<T> {...
should work.)
- paths can now take region parameters, replacing the dirty hack
I was doing before of abusing vstores. vstores are now a bit
of a hack though.
- fix various small bugs:
- we never checked that iface types were compatible when casting
to an iface with `as`
- we allowed nonsense like int<int>
- and more! (actually that may be it)
Most could use the each method, but because of the hack used to
disambiguate old- and new-style loops, some had to use vec::each.
(This hack will go away soon.)
Issue #1619
- we now distinguish bound/free parameters (see region-param
test case for why this is necessary)
- we also track bounds on region variables
- also, restructure fold_ty() to have multiple variants without
duplication instead of one overloaded folder. This also allows
for using block functions.
