This reverts a224bf8ec423b42eea251407e7a6cc8398a5edf4 and fixes the
underlying issue.
The underlying issue is simply that MSVC headers contains a define
like #define __in, where __in is one macro in the MSVC Source
Code Annotation Language, defined in sal.h
Just use a different variable name than __in
__indirectly_readable_impl, and add __in to nasty_macros.h just
like the existing __out.
Please alphabetize. (So that the next person to add an identifier here doesn't have to make any decisions about where to put it "thematically" — it'll be a nice mechanical decision. Plus easy to check for duplicates.)