C++ ABI: Proposed key function tweak

[Martin von Loewis]

> Let's see what other folks say, if anything.

I agree with your analysis that this is not a mere clarification, but
a change to the ABI (exploiting an optimization opportunity).

I also agree that no substantial changes should be made to the ABI at
this point - unless a clear defect in the ABI could be identified
(e.g. if the ABI would not work as specified).

Regards,
Martin