fuzzing: Fuzz different print methods

This is achieved by encoding the type of function used in the first two
bytes.

First byte:
b: buffered

Second byte:
f: formatted

fuzzing/inputs/test9

@@ -1,4 +1,4 @@
-[
+bf[
     [0, -1, 0],
     [1, 0, 0],
     [0, 0, 1]