Account for local rules in specImports
As #23024 (closed) showed, in GHC.Core.Opt.Specialise.specImports
, we were
generating specialisations (a locally-define function) for imported
functions; and then generating specialisations for those
locally-defined functions. The RULE for the latter should be
attached to the local Id, not put in the rules-for-imported-ids
set.
Fix is easy; similar to what happens in GHC.HsToCore.addExportFlagsAndRules