cocoa.messages: Don't import if we don't know the type

cocoa.messages: Don't import if we don't know the type

cmi_simdInt2ValueForKey:defaultValue:found: supposedly returns type "4" which is not published

when bootstrapping, NSDictionary imports 193 methods. when reloading, it imports 460, some of which aren't googleable

just punt if we don't understand the types

! To see the bad type, do this:

"NSDictionary" objc-class
[ nip dup . [ method-name dup "cmi_simdInt2ValueForKey:defaultValue:found:" = [ B ] when . ] [ method-arg-types . ] [ method-return-type . ] tri nl ] each-method-in-class

Related to #2754