#7 Patch to fix building DefMod for RISC OS

[Cameron Cawley]

This is split out from a merge request updating the version of defmod used by the RISC OS Open build system to the latest version, and is based on changes made to the older version by ROOL and/or Pace.

https://gitlab.riscosopen.org/RiscOS/Tools/Sources/GNU/defmod/-/merge_requests/5

The merge request also contains additional changes guarded by a ROOL_BUILD preprocessor check that aren't included in the attached patch.