Move defvars of c-doc-line-join-re + two others from cc-fonts.el to cc-mode.el

This is because these variables are needed at runtime even when cc-fonts.el
hasn't been loaded, as in XEmacs when font locking hasn't been enabled.

* lisp/progmodes/cc-fonts.el (c-doc-line-join-re)
(c-doc-bright-comment-start-re, c-doc-line-join-end-ch): Move definitions to
cc-mode.el.
1 job for master in 55 minutes and 30 seconds (queued for 4 seconds)
Status Job ID Name Coverage
  Test
failed #2255
test-all

00:55:30

 
Name Stage Failure
failed
test-all Test
Makefile:318: recipe for target 'check-doit' failed
make[2]: *** [check-doit] Error 1
make[2]: Leaving directory '/builds/emacs/emacs/test'
Makefile:293: recipe for target 'check-expensive' failed
make[1]: *** [check-expensive] Error 2
make[1]: Leaving directory '/builds/emacs/emacs/test'
Makefile:957: recipe for target 'check-expensive' failed
make: *** [check-expensive] Error 2
ERROR: Job failed: exit code 1