-Note [Loading instances]
-~~~~~~~~~~~~~~~~~~~~~~~~
-We need to make sure that we have at least *read* the interface files
-for any module with an instance decl or RULE that we might want.
-
-* If the instance decl is an orphan, we have a whole separate mechanism
- (loadOprhanModules)
-
-* If the instance decl not an orphan, then the act of looking at the
- TyCon or Class will force in the defining module for the
- TyCon/Class, and hence the instance decl
-
-* BUT, if the TyCon is a wired-in TyCon, we don't really need its interface;
- but we must make sure we read its interface in case it has instances or
- rules. That is what LoadIface.loadWiredInHomeInterface does. It's called
- from TcIface.{tcImportDecl, checkWiredInTyCon, ifCHeckWiredInThing}
-
-All of this is done by the type checker. The renamer plays no role.
-(It used to, but no longer.)
-
-