patch 8.2.1500: Vim9: error when using address without a command

Problem:    Vim9: error when using address without a command.
Solution:   Execute the range itself. (closes #6747)

Author: brammool

src/testdir/test_vim9_script.vim

@@ -10,6 +10,13 @@ def Test_syntax()
   let other: list<string> = ['asdf']
 enddef
 
+def Test_range_only()
+  new
+  setline(1, ['blah', 'Blah'])
+  :/Blah/
+  assert_equal(2, getcurpos()[1])
+enddef
+
 let s:appendToMe = 'xxx'
 let s:addToMe = 111
 let g:existing = 'yes'

src/version.c

@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1500,
 /**/
     1499,
 /**/

src/vim9compile.c

@@ -6661,10 +6661,22 @@ compile_def_function(ufunc_T *ufunc, int set_return_type, cctx_T *outer_cctx)
 	if (*cmd != '\'' || starts_with_colon)
 	{
 	    ea.cmd = skip_range(ea.cmd, NULL);
-	    if (ea.cmd > cmd && !starts_with_colon)
+	    if (ea.cmd > cmd)
 	    {
-		emsg(_(e_colon_required_before_a_range));
-		goto erret;
+		if (!starts_with_colon)
+		{
+		    emsg(_(e_colon_required_before_a_range));
+		    goto erret;
+		}
+		if (ends_excmd2(line, ea.cmd))
+		{
+		    // A range without a command: jump to the line.
+		    // TODO: compile to a more efficient command, possibly
+		    // calling parse_cmd_address().
+		    ea.cmdidx = CMD_SIZE;
+		    line = compile_exec(line, &ea, &cctx);
+		    goto nextline;
+		}
 	    }
 	}
 	p = find_ex_command(&ea, NULL, starts_with_colon ? NULL
@@ -6845,6 +6857,7 @@ compile_def_function(ufunc_T *ufunc, int set_return_type, cctx_T *outer_cctx)
 		    line = compile_exec(line, &ea, &cctx);
 		    break;
 	}
+nextline:
 	if (line == NULL)
 	    goto erret;
 	line = skipwhite(line);