refactor: simplify native-comp detection

Reduce cases where native-comp procedures were executed in
non-native-comp contexts (somehow).

Also:
- Adds a NATIVECOMP constant for statically detecting the feature.
- Remove native-comp-* -> comp-* aliases (Emacs HEAD has long since
  moved on from these).
- Add 'no-native-compile: t' to autoloads file.

core/cli/autoloads.el

@@ -76,7 +76,7 @@ one wants that.")
               (print-quoted t)
               (print-level nil)
               (print-length nil))
-          (insert ";; -*- lexical-binding: t; coding: utf-8; -*-\n"
+          (insert ";; -*- lexical-binding: t; coding: utf-8; no-native-compile: t -*-\n"
                   ";; This file is autogenerated by 'doom sync', DO NOT EDIT IT!!\n")
           (dolist (form (delq nil forms))
             (mapc #'prin1 form))