Is the IWYU mapping of <__fwd/.*> to <fwd>intentional?

I noticed the libc++ include-what-you-use mapping file contains a mapping from <__fwd/.*> to <fwd>, which doesn’t seem right as the <fwd> header doesn’t exist. Is this mapping intentional, and if not, would it be better to skip mapping stuff in __fwd/* entirely, map individual headers in __fwd/ to their corresponding public headers (e.g., <__fwd/string.h><string>), or use a different solution?

Edit: Scratch the first solution, I think there’d have to be some kind of mapping; otherwise, IWYU will just propose #include <__fwd/string.h>, etc.