Update strace to 4.20.

Noteworthy changes in release 4.20 (2017-11-13)
===============================================

* Improvements
  * Implemented decoding of NETLINK_NETFILTER netlink message types and flags.
  * Implemented decoding of SECCOMP_GET_ACTION_AVAIL operation of seccomp
    syscall.
  * Updated lists of ARPHRD_*, BPF_*, ETH_P_*, LOOP_*, MADV_*,
    MEMBARRIER_CMD_*, MFD_*, SECCOMP_*, SO_*, SOL_*, TCP_*, and UFFD_FEATURE_*
    constants.
  * Added decoding of statx syscall on hppa.
  * Updated lists of ioctl commands from Linux 4.14.

* Bug fixes
  * Fixed powerpc personality support on powerpc64.

Bug: N/A
Test: strace date
Change-Id: I9cab638ba737839de4b8b36e4632cf933ba196c4
diff --git a/defs.h b/defs.h
index 34261f2..b1a6b95 100644
--- a/defs.h
+++ b/defs.h
@@ -75,15 +75,6 @@
 extern char *stpcpy(char *dst, const char *src);
 #endif
 
-/* macros */
-#ifndef MAX
-# define MAX(a, b)		(((a) > (b)) ? (a) : (b))
-#endif
-#ifndef MIN
-# define MIN(a, b)		(((a) < (b)) ? (a) : (b))
-#endif
-#define CLAMP(val, min, max) MIN(MAX(min, val), max)
-
 /* Glibc has an efficient macro for sigemptyset
  * (it just does one or two assignments of 0 to internal vector of longs).
  */
@@ -295,6 +286,7 @@
 extern const struct xlat routing_scopes[];
 extern const struct xlat routing_table_ids[];
 extern const struct xlat routing_types[];
+extern const struct xlat seccomp_ret_action[];
 extern const struct xlat setns_types[];
 extern const struct xlat sg_io_info[];
 extern const struct xlat socketlayers[];