cffi 0.17.0 breaks some stuff

Hi,

I'm seeing a bunch of projects that don't seem to work with the latest CFFI release. For example, I get this for a number of projects:

Unhandled CFFI::UNDEFINED-FOREIGN-TYPE-ERROR in thread #<SB-THREAD:THREAD "main thread" RUNNING {1003DD5643}>: Unknown CFFI type :SIZET

That happens in gsll and some other projects.

cl-gtk2 has this:

Unhandled SIMPLE-ERROR in thread #<SB-THREAD:THREAD "main thread" RUNNING {1003DD5663}>: NIL is not a valid symbol for bitfield type #<CFFI::FOREIGN-BITFIELD GOBJECT.FFI:G-TYPE-FLAGS>.

There are other problems in cl-glu.

There's a report here: http://report.quicklisp.org/2016-02-22/failure-report.html

Not all of the problems in the report are directly cffi-related, but many of them are.

Zach