[Bug other/67300] -foffload* undocumented

[burnus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67300

--- Comment #5 from Tobias Burnus <burnus at gcc dot gnu.org> ---
Done: -foffload= and new -foffload-options= are now documented.

To do: Still undocumented:
  -foffload-abi=[lp64|ilp32]