patch 8.2.2394: Vim9: min() and max() return type is "any"

Problem:    Vim9: min() and max() return type is "any".
Solution:   Use return type "number". (closes #7728)
diff --git a/src/testdir/test_vim9_builtin.vim b/src/testdir/test_vim9_builtin.vim
index 06b5ecd..776aec0 100644
--- a/src/testdir/test_vim9_builtin.vim
+++ b/src/testdir/test_vim9_builtin.vim
@@ -655,6 +655,34 @@
   nunmap <F3>
 enddef
 
+def Test_max()
+  g:flag = true
+  var l1: list<number> = g:flag
+          ? [1, max([2, 3])]
+          : [4, 5]
+  assert_equal([1, 3], l1)
+
+  g:flag = false
+  var l2: list<number> = g:flag
+          ? [1, max([2, 3])]
+          : [4, 5]
+  assert_equal([4, 5], l2)
+enddef
+
+def Test_min()
+  g:flag = true
+  var l1: list<number> = g:flag
+          ? [1, min([2, 3])]
+          : [4, 5]
+  assert_equal([1, 2], l1)
+
+  g:flag = false
+  var l2: list<number> = g:flag
+          ? [1, min([2, 3])]
+          : [4, 5]
+  assert_equal([4, 5], l2)
+enddef
+
 def Test_nr2char()
   nr2char(97, true)->assert_equal('a')
 enddef