cmhg 5.42 outputs wrong dependencies when creating C header

If you use the -depend option when generating a header file, then the dependency file will be generated as if you were creating the object file, not the header file. I.e. you’ll get dependencies for o.modhead instead of h.modhead.

I spotted this just now when working on the ZLib module – after copying over an updated VersionNum file and running the makefile it correctly rebuilt o.modhead and linked it into the module, but didn’t bother rebuilding h.modhead or any of the dependent C files due to the missing dependency info.