patch 8.2.1782: Vim9: cannot pass boolean to mapset()

Problem:    Vim9: cannot pass boolean to mapset().
Solution:   Use get_tv_bool(). (closes #7041)

src/map.c

@@ -2307,7 +2307,7 @@ f_mapset(typval_T *argvars, typval_T *rettv UNUSED)
     if (which == NULL)
 	return;
     mode = get_map_mode(&which, 0);
-    is_abbr = (int)tv_get_number(&argvars[1]);
+    is_abbr = (int)tv_get_bool(&argvars[1]);
 
     if (argvars[2].v_type != VAR_DICT)
     {

src/testdir/test_vim9_func.vim

@@ -1721,6 +1721,14 @@ def Test_mapcheck()
   iunabbrev foo
 enddef
 
+def Test_maparg_mapset()
+  nnoremap <F3> :echo "hit F3"<CR>
+  var mapsave = maparg('<F3>', 'n', false, true)
+  mapset('n', false, mapsave)
+
+  nunmap <F3>
+enddef
+
 def Test_nr2char()
   nr2char(97, true)->assert_equal('a')
 enddef

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1782,
 /**/
     1781,
 /**/