GHCi: Don't remove shadowed bindings from typechecker scope.
The shadowed out bindings are accessible via qualified names like Ghci1.foo. Since they are accessable in the renamer the typechecker should be able to see them too. As a consequence they show up in :show bindings. This fixes T11547 Test Plan: Fixed current tests to accomodate to new stuff in :show bindings Added a test that verifies that the typechecker doesn't crash Reviewers: austin, bgamari, simonpj Reviewed By: simonpj Subscribers: simonpj, thomie Differential Revision: https://phabricator.haskell.org/D2447 GHC Trac Issues: #11547