This reverts commit rB3a48147b8ab92, and fixes the issues with linking
etc.
Change compared to previous buggy commit (rBf8d219dfd4c31) is that
new `BlendFileReadReports` reports are now passed to the lowest level
function generating the `FileData` (`filedata_new()`), which ensures
(and asserts) that all code using it does have a valid non-NULL pointer
to a `BlendFileReadReport` data.
Sorry for the noise, it's always when you think a change is trivial and
do not test it well enough that you end up doing those kind of
mistakes...