patch 8.2.4657: errors for functions are sometimes hard to read

Problem:    Errors for functions are sometimes hard to read.
Solution:   Use printable_func_name() in more places.
diff --git a/src/testdir/test_vim9_expr.vim b/src/testdir/test_vim9_expr.vim
index e76e134..38b2afe 100644
--- a/src/testdir/test_vim9_expr.vim
+++ b/src/testdir/test_vim9_expr.vim
@@ -4010,7 +4010,7 @@
   call v9.CheckDefFailure(["echo len('asdf'"], 'E110:', 2)
   call v9.CheckScriptFailure(['vim9script', "echo len('asdf'"], 'E116:', 2)
 
-  call v9.CheckDefAndScriptFailure(["echo Func0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789()"], ['E1011:', 'E117:'], 1)
+  call v9.CheckDefAndScriptFailure(["echo Func01234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789()"], ['E1011:', 'E117:'], 1)
   call v9.CheckDefAndScriptFailure(["echo doesnotexist()"], 'E117:', 1)
 endfunc