Also prefer .emacs.d if .emacs exists

Problem reported by Katsumi Yamaoka (Bug#37456).
* lisp/startup.el (startup--xdg-or-homedot): Also
prefer .emacs.d if a traditional .emacs file exists.
1 job for master in 23 minutes and 51 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
failed #3359
test-all

00:23:51

 
Name Stage Failure
failed
test-all Test
make[2]: *** [cus-load.el] Error 255
Makefile:152: recipe for target 'cus-load.el' failed
make[2]: Leaving directory '/builds/emacs/emacs/lisp'
Makefile:411: recipe for target 'lisp' failed
make[1]: *** [lisp] Error 2
make[1]: Leaving directory '/builds/emacs/emacs'
Makefile:1117: recipe for target 'bootstrap' failed
make: *** [bootstrap] Error 2
ERROR: Job failed: exit code 1