new regset in linux v3.18 for ptrace.
@@ -566,6 +566,7 @@ typedef struct {
#define NT_ARM_TLS 0x401
#define NT_ARM_HW_BREAK 0x402
#define NT_ARM_HW_WATCH 0x403
+#define NT_ARM_SYSTEM_CALL 0x404
#define NT_METAG_CBUF 0x500
#define NT_METAG_RPIPE 0x501
#define NT_METAG_TLS 0x502