Under current implementation, both fields are mostly empty. An immediate consequence is :imports doesn't report anything. Also it causes problems to other components that rely on these fields, such as when defining classes in REPL with -Yrepl-class-based enabled. See issue [SI-9880].

There seem to be a few issues here:

• sym.thisType on a module symbol always returns NoPrefix. Should probably use sym.typeOfThis instead.
• It doesn't handle renames because it won't be able to find the renames in importable members.
• importableMembers may not always be able to return complete list (the case I encountered was with scala.reflect.runtime.universe which has a type of scala.reflect.api.JavaUniverse). Thus we probably should not restrict importedNames to only importableMembers for non-wildcard imports.
• This is caused by typeOfExpression inadvertently changing phase to jvm.