Triggers internal agda error.

[xekoukou]

agda/agda#3805

[xekoukou]

For example, your mergesort implementation does not work anymore.
https://twitter.com/ulfnorell/status/727543430335873028

[UlfNorell]

Fixing in the no-more-with-inliner branch, but blocked on agda/agda#3805/agda/agda#3870.