mksyscall.pl, types_linux.go: regenerate linux {386,amd64} files

Import syscall so that Kill can refer to syscall.Signal.  Drop
termios constants from types_linux.go--all other systems get
them from mkerrors.sh.

Fixes golang/go#8865.

LGTM=r
R=r
CC=golang-codereviews
https://golang.org/cl/152980044

unix/zsysnum_linux_amd64.go

@@ -307,4 +307,13 @@ const (
 	SYS_FANOTIFY_INIT          = 300
 	SYS_FANOTIFY_MARK          = 301
 	SYS_PRLIMIT64              = 302
+	SYS_NAME_TO_HANDLE_AT      = 303
+	SYS_OPEN_BY_HANDLE_AT      = 304
+	SYS_CLOCK_ADJTIME          = 305
+	SYS_SYNCFS                 = 306
+	SYS_SENDMMSG               = 307
+	SYS_SETNS                  = 308
+	SYS_GETCPU                 = 309
+	SYS_PROCESS_VM_READV       = 310
+	SYS_PROCESS_VM_WRITEV      = 311
 )