vim-patch:ae321b5: runtime(vim): Update base-syntax, match shebang lines (vim/vim#15011) (#29351)

Match shebang lines in Vim9 and legacy script.

Mark these as an error if they appear anywhere other than the first line
of a legacy-script file.  In Vim9 script these match as normal line
comments rather than an error.

ae321b51f7

Co-authored-by: dkearns <dougkearns@gmail.com>

runtime/syntax/vim.vim

@@ -828,6 +828,12 @@ endif
 syn match	vimCommentTitle	'"\s*\%([sS]:\|\h\w*#\)\=\u\w*\(\s\+\u\w*\)*:'hs=s+1	contained contains=vimCommentTitleLeader,vimTodo,@vimCommentGroup
 syn match	vim9CommentTitle	'#\s*\%([sS]:\|\h\w*#\)\=\u\w*\(\s\+\u\w*\)*:'hs=s+1	contained contains=vim9CommentTitleLeader,vimTodo,@vimCommentGroup
 
+" allowed anywhere in the file
+if !s:vim9script
+  syn match	vimShebangError	"^\s*\zs#!.*" display
+endif
+syn match	vimShebang	"\%^#!.*" display
+
 syn match	vimContinue		"^\s*\zs\\"
 syn match         vimContinueComment	'^\s*\zs["#]\\ .*'
 syn cluster	vimContinue contains=vimContinue,vimContinueComment
@@ -1058,6 +1064,7 @@ if !exists("skip_vim_syntax_inits")
   hi def link vimHiCtermError	vimError
   hi def link vimHiKeyError	vimError
   hi def link vimMapModErr	vimError
+  hi def link vimShebangError	vimError
   hi def link vimSubstFlagErr	vimError
   hi def link vimSynCaseError	vimError
   hi def link vimSynFoldMethodError	vimError
@@ -1196,6 +1203,7 @@ if !exists("skip_vim_syntax_inits")
  hi def link vimSetSep	Statement
  hi def link vimSetString	vimString
  hi def link vim9Vim9Script	vimCommand
+ hi def link vimShebang	PreProc
  hi def link vimSleep	vimCommand
  hi def link vimSleepArg	Constant
  hi def link vimSleepBang	vimBang