Bug in handling of duplicate exports when exporting T(..)

Summary

In a bug is introduced where the check for duplicate exports is done improperly in case of exporting T(..). I believe the bug is caused by not including the parent name (in this case T) in the list of GREs passed to check_occs from the IEThingAll variant of the lookup_ie function in module GHC.Tc.Gen.Export. I could try looking into it since I'm currently working on that code, or it could be done by someone else.

Steps to reproduce

Try compiling the following code

module Mod (T(), T(..)) where
data T = A | B

Expected behavior

Should warn about duplicate exports

Environment

• GHC version used: master

Optional:

• Operating System: WSL Ubuntu
• System Architecture: x86-64