Disable fixnum>bignum and bignum>fixnum intrinsics since they're not very useful and they increase code size significantly

basis/compiler/cfg/intrinsics/intrinsics.factor

@@ -41,8 +41,8 @@ IN: compiler.cfg.intrinsics
     math.private:fixnum<=
     math.private:fixnum>=
     math.private:fixnum>
-    math.private:bignum>fixnum
-    math.private:fixnum>bignum
+    ! math.private:bignum>fixnum
+    ! math.private:fixnum>bignum
     kernel:eq?
     slots.private:slot
     slots.private:set-slot