Avoid having the async compile log saying it's compiling loaddefs
* lisp/loadup.el (featurep): Define the hash table in nativecomp
builds (but not otherwise). A more natural place to define this
would be in comp.el, but comp.el isn't loaded yet when we load the
.elc file that updates comp--no-native-compile. We could change
the load order and move the definition to comp.el, though.