bug#42906: [feature/native-comp] out-of-tree build process broken

[Ovidiu Toader]

When feature/native-comp branch is built out-of-tree, emacs cannot find the 
.eln files during start.

The patch below fixes this issue. The problem is caused by the fact that during 
an out-of-tree build, default-directory points inside the build tree while the 
.eln files are found in the source tree and because of that the subsequent 
replace-regexp-in-string fails to adjust the file path of the compilation unit.


modified   lisp/loadup.el
@@ -454,7 +454,7 @@
   ;; when installed or if the source directory got moved.  This is set to be
   ;; a pair in the form: (rel-path-from-install-bin . rel-path-from-local-bin).
   (let ((h (make-hash-table :test #'eq))
-        (lisp-src-dir (expand-file-name (concat default-directory "../lisp")))
+        (lisp-src-dir (expand-file-name "lisp" source-directory))
         (bin-dest-dir (cadr (member "--bin-dest" command-line-args)))
         (lisp-dest-dir (cadr (member "--lisp-dest" command-line-args))))
     (mapatoms (lambda (s)