C++11 Requirement for base

[Warner Losh]

It's desirable that C++11 be fully supported in base. I'd like that to
become a hard requirement soon. The jemalloc folks would like to simplify
their code by using C++11  (in such a way that C++ wouldn't be required for
C programs). That is the forcing function to my this message.

The biggest problem doing that is gcc 4.2 still being required for trailing
architectures. I'd like to move from vague plans of "eventually" or "before
12" to be a specific date. I'd propose 12/31/17 as the deadline for the
trailing architectures to have in place a viable external toolchain support
for this as I'd like to remove gcc 4.2 then as well.

Comments?

Warner