So you can now compile C on an Amiga OS 4.1. TBH, I didn't know you couldn't do this before. Most of the Amiga community that I have seen run the 3.X branch on 68k classic machines.
You could do it before. Each version of the 4.0 and 4.1 SDKs came with gcc, but a very very old version (the 4.x series, I believe, ironically enough). What's here is a more recent gcc, as well as VBCC out of box.