Some small compiling fix

See commit description for details, I'm not repeating it all here with different words.

Needs testing before we actually merge the changes in, I don't have anything besides Windows so I can't actually try this fix out for myself sadly. :(

This was originally a quick branch I made to fix a problem so that @wolfy852 could compile with Linux on some thing of his ...turned out not to be the only problem, and then I found a slightly unrelated problem altogether. So it's now a small assortment of compiling-related fixes.

Also should be merged to next, which is hopefully obvious.

Added 1 new commit:

• be266c27 - Removed void typedef for GLPatch_t used when HWRENDER is undefined

Added 1 new commit:

• a8e4234d - Fixed implicit declaration of some functions if compiling without OpenGL support

Okay lol, the branch name is kind of a lie now, it's turned into some random compiling fixes branch or such. Not that it should affect whether all this goes in or not hopefully

Thanks to Alam's help, my compiling issues on Linux have been fixed. config.h.in still errors out when unmodified, but all the other errors I've encountered have suddenly become a thing of the past. I would suggest merging your fix for i_system.c into master and scrapping the rest of the branch, since it seems those errors were only caused by an improper build setup.

Ah, cool. Though I'll merge the other two anyway because 1) that void typedef in w_wad.h is not needed anyway, may as well kill it and 2) these implicit declaration errors I fixed I actually got myself when I tried to compile for Windows SDL2 with NOHW=1

Status changed to merged

mentioned in commit 554c6289