patch 9.0.0430: cannot use repeat() with a blob

Problem:    Cannot use repeat() with a blob.
Solution:   Implement blob repeat. (closes #11090)
diff --git a/src/testdir/test_vim9_func.vim b/src/testdir/test_vim9_func.vim
index c616e18..fce215e 100644
--- a/src/testdir/test_vim9_func.vim
+++ b/src/testdir/test_vim9_func.vim
@@ -2534,6 +2534,12 @@
   res->assert_equal(3)
 
   res = 0
+  for n in repeat(0z01, 3)->blob2list()
+    res += n
+  endfor
+  res->assert_equal(3)
+
+  res = 0
   for n in add([1, 2], 3)
     res += n
   endfor