Originally, you can auto-complete the commands by TAB in M-x.
For example, if you hit M-x, and type "list-*-p", and then hit TAB,
it expands to "list-load-path-shadows", which is very handy.

However, since TAB binds by default to helm-select-action,
if I (global-set-key (kbd "M-x") 'helm-M-x),
I do not know how to do auto-completion (more like guessing) in M-x.

Is there any workaround or configuration I missed?