patch 9.0.0678: using exclamation marks on :function

Problem:    Using exclamation marks on :function.
Solution:   Use :func and :endfunc as usual.

src/testdir/test_vimscript.vim

@@ -719,23 +719,23 @@ endfunc
 
 XpathINIT
 
-function! NULL()
+func NULL()
     Xpath 'a'
     return 0
-endfunction
+endfunc
 
-function! ZERO()
+func ZERO()
     Xpath 'b'
     return 0
-endfunction
+endfunc
 
-function! F0()
+func! F0()
     Xpath 'c'
-endfunction
+endfunc
 
-function! F1(arg)
+func! F1(arg)
     Xpath 'e'
-endfunction
+endfunc
 
 let V0 = 1
 
@@ -6822,10 +6822,10 @@ endfunc
 " Test 95:  lines of :append, :change, :insert			    {{{1
 "-------------------------------------------------------------------------------
 
-function! DefineFunction(name, body)
+func DefineFunction(name, body)
     let func = join(['function! ' . a:name . '()'] + a:body + ['endfunction'], "\n")
     exec func
-endfunction
+endfunc
 
 func Test_script_lines()
     " :append