[Bug 36511] widl fails to build with clang -fsanitize=undefined

https://bugs.winehq.org/show_bug.cgi?id=36511

--- Comment #1 from Austin English  ---
This is with clang 3.4. I see that 1.7.17 (mostly) worked with clang 3.3 in bug
36079. I tried building 1.7.17 with 3.4, but it fails the same as here, in
widl.

I'll try bisecting clang if time permits, but presumably it's an improvement in
its undefined behavior detection.