Pacify byte-compiler in lisp/vc

* lisp/vc/vc-bzr.el, lisp/vc/vc-cvs.el, lisp/vc/vc-hg.el:
* lisp/vc/vc-rcs.el, lisp/vc/vc-src.el:
Declare functions defined elsewhere, to forestall “might not
be defined at runtime” warnings.

lisp/vc/vc-bzr.el

@@ -50,6 +50,11 @@
   (require 'vc-dispatcher)
   (require 'vc-dir))                    ; vc-dir-at-event
 
+(declare-function vc-deduce-fileset "vc"
+                  (&optional observer allow-unregistered
+                             state-model-only-files))
+
+
 ;; Clear up the cache to force vc-call to check again and discover
 ;; new functions when we reload this file.
 (put 'Bzr 'vc-functions nil)

lisp/vc/vc-cvs.el

@@ -27,6 +27,12 @@
 
 (eval-when-compile (require 'vc))
 
+(declare-function vc-branch-p "vc" (rev))
+(declare-function vc-checkout "vc" (file &optional rev))
+(declare-function vc-expand-dirs "vc" (file-or-dir-list backend))
+(declare-function vc-read-revision "vc"
+                  (prompt &optional files backend default initial-input))
+
 ;; Clear up the cache to force vc-call to check again and discover
 ;; new functions when we reload this file.
 (put 'CVS 'vc-functions nil)

lisp/vc/vc-hg.el

@@ -106,6 +106,8 @@
   (require 'vc)
   (require 'vc-dir))
 
+(declare-function vc-compilation-mode "vc-dispatcher" (backend))
+
 ;;; Customization options
 
 (defgroup vc-hg nil

lisp/vc/vc-rcs.el

@@ -41,6 +41,13 @@
   (require 'cl-lib)
   (require 'vc))
 
+(declare-function vc-branch-p "vc" (rev))
+(declare-function vc-read-revision "vc"
+                  (prompt &optional files backend default initial-input))
+(declare-function vc-buffer-context "vc-dispatcher" ())
+(declare-function vc-restore-buffer-context "vc-dispatcher" (context))
+(declare-function vc-setup-buffer "vc-dispatcher" (buf))
+
 (defgroup vc-rcs nil
   "VC RCS backend."
   :version "24.1"

lisp/vc/vc-src.el

@@ -85,6 +85,8 @@
   (require 'cl-lib)
   (require 'vc))
 
+(declare-function vc-setup-buffer "vc-dispatcher" (buf))
+
 (defgroup vc-src nil
   "VC SRC backend."
   :version "25.1"