+133:
+ Trying to compile something like
+ (sb!alien:def-alien-routine "breakpoint_remove" sb!c-call:void
+ (code-obj sb!c-call:unsigned-long)
+ (pc-offset sb!c-call:int)
+ (old-inst sb!c-call:unsigned-long))
+ in SBCL-0.pre7.86.flaky7.22 after warm init fails with an error
+ cannot use values types here
+ probably because the SB-C-CALL:VOID type gets translated to (VALUES).
+ It should be valid to use VOID for a function return type, so perhaps
+ instead of calling SPECIFIER-TYPE (which excludes all VALUES types
+ automatically) we should call VALUES-SPECIFIER-TYPE and handle VALUES
+ types manually, allowing the special case (VALUES) but still excluding
+ all more-complex VALUES types.
+