[lldb] Fix use after free on ModuleList::RemoveSharedModuleIfOrphaned (#155331)
This fixes a potential use after free where
ModuleList::RemoveSharedModuleIfOrphaned ->
SharedModuleList::RemoveIfOrphaned -> SharedModuleList::RemoveFromMap
would potentially dereference a freed pointer. This fixes it by not
calling ModuleList::RemoveSharedModuleIfOrphaned at all if the pointer
was just freed.