sample: dmd while.d
Note this is used in dmd/src/phobos/internal (cast.d, invariant.d, switch.d) to implement certain compiler support functions. Presumably these are used by hardcoding the mangled names into the compiler since no D module can import them. So if this is changed, those modules would have to be renamed and those names would have to be adjusted.
I think that 'fixing' this is probably more trouble than its worth. While such modules do work for internal modules that have no D interface, they won't work anyway for regular D modules, and the user will find that out pretty quick.