std.os.windows: eliminate usage of `usingnamespace`
Some of the structs I shuffled around might be better namespaced under
CONTEXT, I'm not sure. However, for now, this approach preserves
backwards compatibility.
Eliminates one more usage of `usingnamespace` from the standard library.
3 remain.
a7f6e73812mlugg committed on 3/8/2024, 8:02:45 AMparentf4bf061