Allow C modules in Playground Packages

[calebkleveter]

[calebkleveter]

It might be possible to figure out what C headers go to module by reading the packages build output:

Compile CNIOLinux shim.c
Compile CNIOSHA1 c_nio_sha1.c
Compile CNIOZlib empty.c
Compile CNIOOpenSSL shims.c
...
Compile CNIOOpenSSL helpers.c
Compile CNIOHTTPParser c_nio_http_parser.c
Compile CNIODarwin shim.c
Compile CNIOAtomics src/c-atomics.c
Compile CCryptoOpenSSL shim.c
Compile CBcrypt blf.c
Compile CBcrypt bcrypt.c
Compile CBase32 base32.c