runtime(vim): Update base syntax, match :prompt command args

closes: #18732

Signed-off-by: Doug Kearns <dougkearns@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/syntax/testdir/input/vim_ex_prompt_commands.vim

@@ -0,0 +1,46 @@
+" Vim :prompt{find,repl} commands
+
+
+promptfind foo
+promptrepl foo
+
+promptfind a
+      \ really
+      \ long
+      \ search
+      \ string
+promptrepl a
+      \ really
+      \ long
+      \ search
+      \ string
+
+
+" no tail comment or trailing bar
+
+promptfind foo " more search string
+promptfind foo | more search string
+
+
+def Vim9Context()
+  promptfind foo
+  promptrepl foo
+
+  promptfind a
+	\ really
+	\ long
+	\ search
+	\ string
+  promptrepl a
+	\ really
+	\ long
+	\ search
+	\ string
+
+
+  # no tail comment or trailing bar
+
+  promptfind foo # more search string
+  promptfind foo | more search string
+enddef
+