Fix byte compilation of package built-ins

Fix byte compilation of package built-ins

* lisp/emacs-lisp/package.el
(package--activate-autoloads-and-load-path):
(package--load-files-for-activation): Remove.
(package--library-stem): New function, because
file-name-sans-extension is insufficient.
(package--reload-previously-loaded): New function.
(package-activate-1): Reload directly.
(package--files-load-history):
(package--list-of-conflicts):
(package--list-loaded-files): Remove
(package-unpack): Adjust call.

* test/lisp/emacs-lisp/package-tests.el (macro-builtin-func): Test.
(macro-builtin-10-and-90): Test.
(package-test-macro-compilation): Test.
(package-test-macro-compilation-gz): Test (bug#49708).