[RFD] Using the 'memory constraint' trick to avoid memory clobber doesn't work

[David Wohlferd]

> Can you please file a bug in bugzilla if you haven't already done so?
> We can still fix bugs during the next three months ;)

Well, I opened one.  Briefly.

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63900

dw