patch 8.2.1142: Vim9: return type of insert() is any

Problem:    Vim9: return type of insert() is any.
Solution:   Use type of the first argument.

src/evalfunc.c

@@ -667,7 +667,7 @@ static funcentry_T global_functions[] =
     {"inputrestore",	0, 0, 0,	  ret_number,	f_inputrestore},
     {"inputsave",	0, 0, 0,	  ret_number,	f_inputsave},
     {"inputsecret",	1, 2, FEARG_1,	  ret_string,	f_inputsecret},
-    {"insert",		2, 3, FEARG_1,	  ret_any,	f_insert},
+    {"insert",		2, 3, FEARG_1,	  ret_first_arg, f_insert},
     {"interrupt",	0, 0, 0,	  ret_void,	f_interrupt},
     {"invert",		1, 1, FEARG_1,	  ret_number,	f_invert},
     {"isdirectory",	1, 1, FEARG_1,	  ret_number,	f_isdirectory},

src/testdir/test_vim9_func.vim

@@ -918,6 +918,15 @@ def Test_extend_return_type()
   assert_equal(6, res)
 enddef
 
+def Test_insert_return_type()
+  let l = insert([2, 1], 3)
+  let res = 0
+  for n in l
+    res += n
+  endfor
+  assert_equal(6, res)
+enddef
+
 def Test_filter_return_type()
   let l = filter([1, 2, 3], {-> 1})
   let res = 0

src/version.c

@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1142,
 /**/
     1141,
 /**/