tree 2ee59f13d8224ff90fc5ce007537e026d0c71280
parent facc64ad0c68bf2c0009b26b849ce6a7487215a5
author Shawn Pearce <sop@google.com> 1426304965 -0700
committer Shawn Pearce <sop@google.com> 1426304965 -0700

Fix backtracking for arity-2 predicates

In commit d53fd3122110ad5440de6b8a4edfe65a17d6f457 there
was an accidental removal restoring the continuation when
a /2 predicate backtracked to try another choice point.

Put back the missing "engine.cont = this.cont" register.

Change-Id: I244c3e2564cff04fef51afdcecb413617f7adae8