KevinBuhr authored Aug 21, 2018 and Ben Gamari committed Aug 21, 2018

If `findIndices` is marked INLINE in `Data.OldList`, then the unfolded
versions of `elemIndex` and `findIndex` included in the interface file
are unfusible (even though `findIndices` itself remains fusible).  By
marking it INLINABLE instead, elemIndex` and `findIndex` will fuse
properly.

Test Plan: make TEST=T15426

Reviewers: hvr, bgamari

Reviewed By: bgamari

Subscribers: rwbarton, carter

GHC Trac Issues: #15426

Differential Revision: https://phabricator.haskell.org/D5063