win: fix ObjectWrap for latest v8
win: fix ObjectWrap for latest v8

We need to keep ObjectWrap around for module authors (we think), but
v8 3.21 broke node_object_wrap.h with respect to MSVC. Coincidentally,
we no longer use ObjectWrap at all in core, and native modules might
as well use their own entirely internal implementation if they need it.

dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node