patch 8.2.3438: cannot manipulate blobs

Problem:    Cannot manipulate blobs.
Solution:   Add blob2list() and list2blob(). (Yegappan Lakshmanan,
            closes #8868)
diff --git a/src/testdir/test_vim9_builtin.vim b/src/testdir/test_vim9_builtin.vim
index 5f22b33..746d3f8 100644
--- a/src/testdir/test_vim9_builtin.vim
+++ b/src/testdir/test_vim9_builtin.vim
@@ -287,6 +287,10 @@
   assert_fails('balloon_split(true)', 'E1174:')
 enddef
 
+def Test_blob2list()
+  CheckDefAndScriptFailure2(['blob2list(10)'], 'E1013: Argument 1: type mismatch, expected blob but got number', 'E1238: Blob required for argument 1')
+enddef
+
 def Test_browse()
   CheckFeature browse
 
@@ -572,6 +576,7 @@
   assert_equal(97, char2nr('a', 0))
   assert_equal(97, char2nr('a', true))
   assert_equal(97, char2nr('a', false))
+  char2nr('')->assert_equal(0)
 enddef
 
 def Test_charclass()
@@ -786,6 +791,8 @@
   CheckDefAndScriptFailure2(['escape(true, false)'], 'E1013: Argument 1: type mismatch, expected string but got bool', 'E1174: String required for argument 1')
   CheckDefAndScriptFailure2(['escape("a", 10)'], 'E1013: Argument 2: type mismatch, expected string but got number', 'E1174: String required for argument 2')
   assert_equal('a\:b', escape("a:b", ":"))
+  escape('abc', '')->assert_equal('abc')
+  escape('', ':')->assert_equal('')
 enddef
 
 def Test_eval()
@@ -1921,6 +1928,11 @@
   assert_equal(0, lispindent(1))
 enddef
 
+def Test_list2blob()
+  CheckDefAndScriptFailure2(['list2blob(10)'], 'E1013: Argument 1: type mismatch, expected list<number> but got number', 'E1211: List required for argument 1')
+  CheckDefFailure(['list2blob([0z10, 0z02])'], 'E1013: Argument 1: type mismatch, expected list<number> but got list<blob>')
+enddef
+
 def Test_list2str_str2list_utf8()
   var s = "\u3042\u3044"
   var l = [0x3042, 0x3044]