Revert "This future was solved by my _defaultOf language feature, I believe due to the"

This reverts commit 9e7646b1e5ee6feb7de48788ad465c43620ae03a.

Reverting the removal of this feature, since the general solution involves
inserting reference temps where needed.  This problem may be cured by a more
complete merge with the defaultOf work.  For now, reinstating the future just
puts it out of the way temporarily.