Update runtime files.
diff --git a/runtime/syntax/c.vim b/runtime/syntax/c.vim
index 1143ca7..95d3455 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:	2017 Apr 30
+" Last Change:	2018 Sep 21
 
 " Quit when a (custom) syntax file was already loaded
 if exists("b:current_syntax")
@@ -220,7 +220,7 @@
   syn match	cCommentSkip	contained "^\s*\*\($\|\s\+\)"
   syn region cCommentString	contained start=+L\=\\\@<!"+ skip=+\\\\\|\\"+ end=+"+ end=+\*/+me=s-1 contains=cSpecial,cCommentSkip
   syn region cComment2String	contained start=+L\=\\\@<!"+ skip=+\\\\\|\\"+ end=+"+ end="$" contains=cSpecial
-  syn region  cCommentL	start="//" skip="\\$" end="$" keepend contains=@cCommentGroup,cComment2String,cCharacter,cNumbersCom,cSpaceError,@Spell
+  syn region  cCommentL	start="//" skip="\\$" end="$" keepend contains=@cCommentGroup,cComment2String,cCharacter,cNumbersCom,cSpaceError,cWrongComTail,@Spell
   if exists("c_no_comment_fold")
     " Use "extend" here to have preprocessor lines not terminate halfway a
     " comment.
@@ -239,6 +239,7 @@
 " keep a // comment separately, it terminates a preproc. conditional
 syn match	cCommentError	display "\*/"
 syn match	cCommentStartError display "/\*"me=e-1 contained
+syn match	cWrongComTail	display "\*/"
 
 syn keyword	cOperator	sizeof
 if exists("c_gnu")
@@ -453,6 +454,7 @@
 hi def link cCommentError	cError
 hi def link cCommentStartError	cError
 hi def link cSpaceError		cError
+hi def link cWrongComTail	cError
 hi def link cSpecialError	cError
 hi def link cCurlyError		cError
 hi def link cOperator		Operator