patch 8.2.1132: Vim9: return type of repeat() is not specific enough

Problem:    Vim9: return type of repeat() is not specific enough.
Solution:   Return the type of the first argument. (closes #6395)
diff --git a/src/testdir/test_vim9_func.vim b/src/testdir/test_vim9_func.vim
index 583a232..e8d712f 100644
--- a/src/testdir/test_vim9_func.vim
+++ b/src/testdir/test_vim9_func.vim
@@ -596,6 +596,14 @@
   assert_equal(13, funcResult)
 enddef
 
+def Test_repeat_return_type()
+  let res = 0
+  for n in repeat([1], 3)
+    res += n
+  endfor
+  assert_equal(3, res)
+enddef
+
 def Test_func_type_part()
   let RefVoid: func: void
   RefVoid = FuncNoArgNoRet