It doesn't. While that doesn't bother me (I'm always writing new libs), I will share what libs I do create for it.. if that helps. I ~might~ port some of the more general lib stuffs from HuC over, but they'll probably be re-writes or something comparable-ish (rather than directly compatible). I usually write specific lib code (to what I need), rather than generalized lib stuffs. Not sure how useful that will be.
CC specifically had strengths for managing banks/pages of C functions, which setups nicely with the extra ram for the SGX (or PCE CD game projects with >8k segment of fixed 'ram'). That, and the variable size chunks of banks/data setups you can mix on the fly (16kCode/16kData, or 24kCode/8kData, etc). I wanted to write something in C-ish for PCE, so I'm gonna go with this. Chilly Willy is pretty good with creating/setting up lib packs IIRC. Of course, if I can get him to actually start SGX dev stuffs.
I'm just starting to set this up. I have no idea what kind of code generation CC spits out. Hopefully nothing worse than HuC.