[spec] s/merge causes failure to roundtrip conform then unform

Description

Opened the bug after discussion in this thread: https://groups.google.com/forum/#!topic/clojure/r8WO24rHsi0

Essentially, when using s/merge with s/or, s/conform returns a structure that cannot be s/unform'ed.

Steps to reproduce (shamelessly copied from the thread):

Environment

linux

Assignee

Unassigned

Reporter

import

Labels

Approval

Triaged

Patch

None

Affects versions

Priority

Major