Please revert libc Symbol.map / Versions.def changes

[David Shao]

Please revert recent changes:

commit 626c9d706f1bffc498cc5ffda1baefba2677d693
Date:   Fri Feb 3 19:06:39 2017 +0100

    libc/sys: Clean up Symbol.map for the recent get/setaffinity work.

commit 61d257f12c46320896dfabdce3ba0591d62e06ff
Date:   Fri Feb 3 19:14:40 2017 +0100

    libc: Adjust Versions.def.

These somehow break the most basic compilation in userland
such as compiling pkgsrc devel/cmake which suddenly
claims it can't find unordered_map in std::.

After a reversion back to

commit 22f4a817164aa428518102732730fadabc37b8eb
Date:   Tue Jan 31 18:33:33 2017 -0800

    kernel - Avoid p->p_token when sending a signal to a particular lwp

all seems well.

Using the kernel post the previous changes doesn't exactly
seem a bed of roses either with constant lockups on
an Intel Ivybridge machine, even trying to do a simple
make -j7 buildworld