Write the header for an application-specific extension of 8 data bytes

After writing the header, clients should write the 8 data bytes.

Property definitions

msgpack :: write $ Writer :: write_msgpack_fixext8
	# Write the header for an application-specific extension of 8 data bytes
	#
	# After writing the header, clients should write the 8 data bytes.
	fun write_msgpack_fixext8(typ: Int)
	do
		write_byte 0xD7
		write_byte typ
	end
lib/msgpack/write.nit:475,2--482,4