patch 8.0.0118
Problem:    "make proto" adds extra function prototype.
Solution:   Add #ifdef.
diff --git a/runtime/syntax/c.vim b/runtime/syntax/c.vim
index cc99f67..16c7ce4 100644
--- a/runtime/syntax/c.vim
+++ b/runtime/syntax/c.vim
@@ -1,7 +1,7 @@
 " Vim syntax file
 " Language:	C
 " Maintainer:	Bram Moolenaar <Bram@vim.org>
-" Last Change:	2016 Nov 17
+" Last Change:	2016 Nov 18
 
 " Quit when a (custom) syntax file was already loaded
 if exists("b:current_syntax")
@@ -363,23 +363,23 @@
 if !exists("c_no_if0")
   syn cluster	cCppOutInGroup	contains=cCppInIf,cCppInElse,cCppInElse2,cCppOutIf,cCppOutIf2,cCppOutElse,cCppInSkip,cCppOutSkip
   syn region	cCppOutWrapper	start="^\s*\zs\(%:\|#\)\s*if\s\+0\+\s*\($\|//\|/\*\|&\)" end=".\@=\|$" contains=cCppOutIf,cCppOutElse,@NoSpell fold
-  syn region	cCppOutIf	contained start="0\+" matchgroup=cCppOutWrapper end="^\s*\zs\(%:\|#\)\s*endif\>" contains=cCppOutIf2,cCppOutElse
+  syn region	cCppOutIf	contained start="0\+" matchgroup=cCppOutWrapper end="^\s*\(%:\|#\)\s*endif\>" contains=cCppOutIf2,cCppOutElse
   if !exists("c_no_if0_fold")
     syn region	cCppOutIf2	contained matchgroup=cCppOutWrapper start="0\+" end="^\s*\(%:\|#\)\s*\(else\>\|elif\s\+\(0\+\s*\($\|//\|/\*\|&\)\)\@!\|endif\>\)"me=s-1 contains=cSpaceError,cCppOutSkip,@Spell fold
   else
     syn region	cCppOutIf2	contained matchgroup=cCppOutWrapper start="0\+" end="^\s*\(%:\|#\)\s*\(else\>\|elif\s\+\(0\+\s*\($\|//\|/\*\|&\)\)\@!\|endif\>\)"me=s-1 contains=cSpaceError,cCppOutSkip,@Spell
   endif
-  syn region	cCppOutElse	contained matchgroup=cCppOutWrapper start="^\s*\zs\(%:\|#\)\s*\(else\|elif\)" end="^\s*\zs\(%:\|#\)\s*endif\>"me=s-1 contains=TOP,cPreCondit
+  syn region	cCppOutElse	contained matchgroup=cCppOutWrapper start="^\s*\(%:\|#\)\s*\(else\|elif\)" end="^\s*\(%:\|#\)\s*endif\>"me=s-1 contains=TOP,cPreCondit
   syn region	cCppInWrapper	start="^\s*\zs\(%:\|#\)\s*if\s\+0*[1-9]\d*\s*\($\|//\|/\*\||\)" end=".\@=\|$" contains=cCppInIf,cCppInElse fold
-  syn region	cCppInIf	contained matchgroup=cCppInWrapper start="\d\+" end="^\s*\zs\(%:\|#\)\s*endif\>" contains=TOP,cPreCondit
+  syn region	cCppInIf	contained matchgroup=cCppInWrapper start="\d\+" end="^\s*\(%:\|#\)\s*endif\>" contains=TOP,cPreCondit
   if !exists("c_no_if0_fold")
-    syn region	cCppInElse	contained start="^\s*\zs\(%:\|#\)\s*\(else\>\|elif\s\+\(0*[1-9]\d*\s*\($\|//\|/\*\||\)\)\@!\)" end=".\@=\|$" containedin=cCppInIf contains=cCppInElse2 fold
+    syn region	cCppInElse	contained start="^\s*\(%:\|#\)\s*\(else\>\|elif\s\+\(0*[1-9]\d*\s*\($\|//\|/\*\||\)\)\@!\)" end=".\@=\|$" containedin=cCppInIf contains=cCppInElse2 fold
   else
-    syn region	cCppInElse	contained start="^\s*\zs\(%:\|#\)\s*\(else\>\|elif\s\+\(0*[1-9]\d*\s*\($\|//\|/\*\||\)\)\@!\)" end=".\@=\|$" containedin=cCppInIf contains=cCppInElse2
+    syn region	cCppInElse	contained start="^\s*\(%:\|#\)\s*\(else\>\|elif\s\+\(0*[1-9]\d*\s*\($\|//\|/\*\||\)\)\@!\)" end=".\@=\|$" containedin=cCppInIf contains=cCppInElse2
   endif
-  syn region	cCppInElse2	contained matchgroup=cCppInWrapper start="^\s*\zs\(%:\|#\)\s*\(else\|elif\)\([^/]\|/[^/*]\)*" end="^\s*\zs\(%:\|#\)\s*endif\>"me=s-1 contains=cSpaceError,cCppOutSkip,@Spell
-  syn region	cCppOutSkip	contained start="^\s*\zs\(%:\|#\)\s*\(if\>\|ifdef\>\|ifndef\>\)" skip="\\$" end="^\s*\zs\(%:\|#\)\s*endif\>" contains=cSpaceError,cCppOutSkip
-  syn region	cCppInSkip	contained matchgroup=cCppInWrapper start="^\s*\zs\(%:\|#\)\s*\(if\s\+\(\d\+\s*\($\|//\|/\*\||\|&\)\)\@!\|ifdef\>\|ifndef\>\)" skip="\\$" end="^\s*\zs\(%:\|#\)\s*endif\>" containedin=cCppOutElse,cCppInIf,cCppInSkip contains=TOP,cPreProc
+  syn region	cCppInElse2	contained matchgroup=cCppInWrapper start="^\s*\(%:\|#\)\s*\(else\|elif\)\([^/]\|/[^/*]\)*" end="^\s*\(%:\|#\)\s*endif\>"me=s-1 contains=cSpaceError,cCppOutSkip,@Spell
+  syn region	cCppOutSkip	contained start="^\s*\(%:\|#\)\s*\(if\>\|ifdef\>\|ifndef\>\)" skip="\\$" end="^\s*\(%:\|#\)\s*endif\>" contains=cSpaceError,cCppOutSkip
+  syn region	cCppInSkip	contained matchgroup=cCppInWrapper start="^\s*\(%:\|#\)\s*\(if\s\+\(\d\+\s*\($\|//\|/\*\||\|&\)\)\@!\|ifdef\>\|ifndef\>\)" skip="\\$" end="^\s*\(%:\|#\)\s*endif\>" containedin=cCppOutElse,cCppInIf,cCppInSkip contains=TOP,cPreProc
 endif
 syn region	cIncluded	display contained start=+"+ skip=+\\\\\|\\"+ end=+"+
 syn match	cIncluded	display contained "<[^>]*>"