.mld file errors are off by one

[dbuenzli]

Sample:

[doc-build odoc][0]: (brzo log --id 66)
File "/Users/dbuenzli/sync/repos/uucp/doc/unicode.mld", line 382, characters 35-52:
Failed to resolve reference unresolvedroot(Stdlib).Uchar.t Couldn't find "Stdlib"

This points to the line before the actual reference.

[asavahista]

i think this is the source:

odoc/src/loader/odoc_loader.ml

Line 7 in 79ee613

Lexing.{ pos_fname = filename; pos_lnum = 0; pos_cnum = 0; pos_bol = 0 }

this is in agreement with zero_pos in the stdlib.
changing pos_lnum from 0 to 1 works for the example given so i believe it is the issue, but i'm not sure so i won't be opening a pr (at least until someone can confirm) - it shouldn't be hard to make the pr anyway

[asavahista]

pr has been merged so this should be fixed in master

[dbuenzli]

Thanks @asavahista !