fix native function definition

Author: douyixuan

pkg/ckb/native.cell

@@ -1,8 +1,15 @@
 package ckb
 
+type ByteSlice table {
+	len		uint32
+	cap		uint32
+	offset 	uint32
+	ptr 	*uint8
+}
+
 extern (
-	func __slice_get_ptr(s uintptr) *uint8
-	func __slice_set_len(s uintptr, size uint32)
+	func __slice_get_ptr(s *ByteSlice) *uint8
+	func __slice_set_len(s *ByteSlice, size uint32)
 	// reference from ckb_syscall_apis.h
 	func ckb_load_tx_hash(addr *uint8, len *uint64, offset uint) int
 	func ckb_load_transaction(addr *uint8, len *uint64, offset uint) int