patch 8.2.4940: some code is never used

Problem:    Some code is never used.
Solution:   Remove dead code.  Add a few more test cases.

src/proto/vim9expr.pro

@@ -2,7 +2,7 @@
 int generate_ppconst(cctx_T *cctx, ppconst_T *ppconst);
 void clear_ppconst(ppconst_T *ppconst);
 int compile_member(int is_slice, int *keeping_dict, cctx_T *cctx);
-int compile_load_scriptvar(cctx_T *cctx, char_u *name, char_u *start, char_u **end, int error);
+int compile_load_scriptvar(cctx_T *cctx, char_u *name, char_u *start, char_u **end);
 int compile_load(char_u **arg, char_u *end_arg, cctx_T *cctx, int is_expr, int error);
 char_u *to_name_end(char_u *arg, int use_namespace);
 char_u *to_name_const_end(char_u *arg);

src/testdir/test_vim9_builtin.vim

@@ -4083,6 +4083,11 @@ def Test_substitute()
     assert_equal("4", substitute("3", '\d', '\=str2nr(submatch(0)) + 1', 'g'))
   END
   v9.CheckDefAndScriptSuccess(lines)
+
+  lines =<< trim END
+    assert_equal("4", substitute("3", '\d', '\="text" x', 'g'))
+  END
+  v9.CheckDefAndScriptFailure(lines, 'E488: Trailing characters: x')
 enddef
 
 def Test_swapinfo()

src/testdir/test_vim9_expr.vim

@@ -2695,6 +2695,21 @@ def Test_expr8funcref()
       Test()
   END
   v9.CheckScriptSuccess(lines)
+
+  # using funcref in legacy script
+  lines =<< trim END
+      def s:Refme(): string
+        return 'yes'
+      enddef
+
+      def TestFunc()
+        var TheRef = s:Refme
+        assert_equal('yes', TheRef())
+      enddef
+
+      call TestFunc()
+  END
+  v9.CheckScriptSuccess(lines)
 enddef
 
 let g:test_space_dict = {'': 'empty', ' ': 'space'}

src/version.c

@@ -746,6 +746,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4940,
 /**/
     4939,
 /**/

src/vim9compile.c

@@ -1140,7 +1140,7 @@ generate_loadvar(
 	    break;
 	case dest_script:
 	    compile_load_scriptvar(cctx,
-		    name + (name[1] == ':' ? 2 : 0), NULL, NULL, TRUE);
+				  name + (name[1] == ':' ? 2 : 0), NULL, NULL);
 	    break;
 	case dest_env:
 	    // Include $ in the name here

src/vim9expr.c

@@ -140,9 +140,8 @@ compile_member(int is_slice, int *keeping_dict, cctx_T *cctx)
 	    typep->type_curr = &t_any;
 	    typep->type_decl = &t_any;
 	}
-	if (may_generate_2STRING(-1, FALSE, cctx) == FAIL)
-	    return FAIL;
-	if (generate_instr_drop(cctx, ISN_MEMBER, 1) == FAIL)
+	if (may_generate_2STRING(-1, FALSE, cctx) == FAIL
+		|| generate_instr_drop(cctx, ISN_MEMBER, 1) == FAIL)
 	    return FAIL;
 	if (keeping_dict != NULL)
 	    *keeping_dict = TRUE;
@@ -246,8 +245,7 @@ compile_load_scriptvar(
 	cctx_T *cctx,
 	char_u *name,	    // variable NUL terminated
 	char_u *start,	    // start of variable
-	char_u **end,	    // end of variable, may be NULL
-	int    error)	    // when TRUE may give error
+	char_u **end)	    // end of variable, may be NULL
 {
     scriptitem_T    *si;
     int		    idx;
@@ -368,14 +366,10 @@ compile_load_scriptvar(
 	return OK;
     }
 
-    if (idx == -1 || si->sn_version != SCRIPT_VERSION_VIM9)
-	// variable is not in sn_var_vals: old style script.
+    // Can only get here if we know "name" is a script variable and not in a
+    // Vim9 script (variable is not in sn_var_vals): old style script.
     return generate_OLDSCRIPT(cctx, ISN_LOADS, name, current_sctx.sc_sid,
 								       &t_any);
-
-    if (error)
-	semsg(_(e_item_not_found_str), name);
-    return FAIL;
 }
 
     static int
@@ -462,7 +456,7 @@ compile_load(
 			      res = generate_funcref(cctx, name, FALSE);
 			  else
 			      res = compile_load_scriptvar(cctx, name,
-							    NULL, &end, error);
+								   NULL, &end);
 			  break;
 		case 'g': if (vim_strchr(name, AUTOLOAD_CHAR) == NULL)
 			  {
@@ -538,7 +532,7 @@ compile_load(
 		// already exists in a Vim9 script or when it's imported.
 		if (script_var_exists(*arg, len, cctx, NULL) == OK
 				      || find_imported(name, 0, FALSE) != NULL)
-		   res = compile_load_scriptvar(cctx, name, *arg, &end, FALSE);
+		   res = compile_load_scriptvar(cctx, name, *arg, &end);
 
 		// When evaluating an expression and the name starts with an
 		// uppercase letter it can be a user defined function.