swift234

stdlib: define `WIN32_LEAN_AND_MEAN` and `NOMINMAX`

`WIN32_LEAN_AND_MEAN` prevents "rarely-used" headers from being pulled in.  This
significantly reduced preprocessor pressure, speeding up compile.  It also
reduces the amount of cruft pulled in by the Windows.h.

`NOMINMAX` ensures that the `min` and `max` macros are not defined.  These
macros collide with the use of `min` and `max` from C++ in certain cases: e.g.
`std::limits<T>`.