Add spec to test that typedefs do not prevent builtin types from being used in function signatures.
Add spec to test that typedefs do not prevent builtin types from being used in function signatures.

sparkchaser/ffi,MikaelSmith/ffi,ffi/ffi,tduehr/ffi,tduehr/ffi,mvz/ffi,yghannam/ffi,mvz/ffi,majioa/ffi,ffi/ffi,ferventcoder/ffi,majioa/ffi,yghannam/ffi,majioa/ffi,ferventcoder/ffi,yghannam/ffi,ferventcoder/ffi,MikaelSmith/ffi,sparkchaser/ffi,yghannam/ffi,ferventcoder/ffi,MikaelSmith/ffi,sparkchaser/ffi,mvz/ffi,yghannam/ffi,ffi/ffi,tduehr/ffi,sparkchaser/ffi,MikaelSmith/ffi,tduehr/ffi,mvz/ffi,majioa/ffi