In the docs it says you can produce SWFs with -emit-swf
To generate a SWF, the executable format suitable for use in the Flash Runtime, you pass the -emit-swf argument to GCC:
gcc -emit-swf hello.c -o hello.swf
and SWCs with -emit-swc
-emit-swc= Emits a SWC that can be linked into a Flash Builder project or distributed for others to link into their own projects. You must specify the namespace that you want to use to replace the default com.adobe.flascc namespace, this lets you link multiple FlasCC-generated SWCs into a single project.
Note that you'll need to write some kind of shim layer api for your AS3 code, or you can automate it with SWIG.