patch 8.2.4365: sticky command modifiers are too sticky

Problem:    sticky command modifiers are too sticky.
Solution:   Do not apply command modifiers to a called function. (closes #9751)

src/testdir/test_vim9_cmd.vim

@@ -118,6 +118,20 @@ def Test_cmdmod_execute()
   END
   v9.CheckScriptSuccess(lines)
   delete('Xvim9import.vim')
+
+  # "legacy" does not aply to a called function
+  lines =<< trim END
+      vim9script
+
+      def g:TheFunc()
+        if exists('something')
+          echo 'yes'
+        endif
+      enddef
+      legacy exe 'call g:TheFunc()'
+  END
+  v9.CheckScriptSuccess(lines)
+  delfunc g:TheFunc
 enddef
 
 def Test_edit_wildcards()

src/userfunc.c

@@ -2513,6 +2513,7 @@ call_user_func(
 {
     sctx_T	save_current_sctx;
     int		using_sandbox = FALSE;
+    int		save_sticky_cmdmod_flags = sticky_cmdmod_flags;
     funccall_T	*fc;
     int		save_did_emsg;
     int		default_arg_err = FALSE;
@@ -2569,6 +2570,7 @@ call_user_func(
 	if (do_profiling == PROF_YES)
 	    profile_may_start_func(&profile_info, fp, caller);
 #endif
+	sticky_cmdmod_flags = 0;
 	call_def_function(fp, argcount, argvars, funcexe->fe_partial, rettv);
 	funcdepth_decrement();
 #ifdef FEAT_PROFILE
@@ -2578,6 +2580,7 @@ call_user_func(
 #endif
 	current_funccal = fc->caller;
 	free_funccal(fc);
+	sticky_cmdmod_flags = save_sticky_cmdmod_flags;
 	return;
     }
 
@@ -2797,6 +2800,9 @@ call_user_func(
 				 fc->caller == NULL ? NULL : fc->caller->func);
 #endif
 
+    // "legacy" does not apply to commands in the function
+    sticky_cmdmod_flags = 0;
+
     save_current_sctx = current_sctx;
     current_sctx = fp->uf_script_ctx;
     save_did_emsg = did_emsg;
@@ -2889,6 +2895,7 @@ call_user_func(
 #endif
     if (using_sandbox)
 	--sandbox;
+    sticky_cmdmod_flags = save_sticky_cmdmod_flags;
 
     if (p_verbose >= 12 && SOURCING_NAME != NULL)
     {

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4365,
 /**/
     4364,
 /**/