Turn "ambiguous import" error into a panic

This error should never occur, as a lookup of a type or data constructor
should never be ambiguous. This is because a single module cannot export
multiple Names with the same OccName, as per item (1) of
Note [Exporting duplicate declarations] in GHC.Tc.Gen.Export.

This code path was intended to handle duplicate record fields, but the
rest of the code had since been refactored to handle those in a
different way.

We also remove the AmbiguousImport constructor of IELookupError, as
it is no longer used.

Fixes #23302

0 files changed, 0 insertions, 0 deletions