Moved pending tests that work into pos and neg.

One test (t2613) required lifting a hard recursion limit in findMember
(used for debug only, will be removed in the future). The same test
also requires -Yno-deep-subtypes to be reset, so it's in pos_special
instead of pos.
Merge pull request #233 from dotty-staging/cleanup/tests

Moved pending tests that work into pos and neg.