Revert of Non-SFI mode: Add Linux asynchronous signal support

src/public/linux_syscalls/sys/syscall.h

 /*
  * Copyright (c) 2015 The Native Client Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef NATIVE_CLIENT_SRC_PUBLIC_LINUX_SYSCALLS_SYS_SYSCALLS_H_
 #define NATIVE_CLIENT_SRC_PUBLIC_LINUX_SYSCALLS_SYS_SYSCALLS_H_ 1
 
 #ifdef __cplusplus
@@ skipping 53 matching lines @@
 # define __NR_pwrite64           181
 # define __NR_getcwd             183
 # define __NR_ugetrlimit         191
 # define __NR_mmap2              192
 # define __NR_truncate64         193
 # define __NR_stat64             195
 # define __NR_lstat64            196
 # define __NR_fstat64            197
 # define __NR_getdents64         220
 # define __NR_fcntl64            221
-# define __NR_gettid             224
 # define __NR_futex              240
 # define __NR_set_thread_area    243
 # define __NR_exit_group         252
 # define __NR_clock_gettime      265
 # define __NR_clock_getres       266
-# define __NR_tgkill             270
 # define __NR_utimes             271
 # define __NR_openat             295
 # define __NR_fstatat64          300
 
 #elif defined(__arm__)
 
 # define __NR_exit               1
 # define __NR_read               3
 # define __NR_write              4
 # define __NR_open               5
@@ skipping 35 matching lines @@
 # define __NR_pwrite64           181
 # define __NR_getcwd             183
 # define __NR_ugetrlimit         191
 # define __NR_mmap2              192
 # define __NR_truncate64         193
 # define __NR_stat64             195
 # define __NR_lstat64            196
 # define __NR_fstat64            197
 # define __NR_getdents64         217
 # define __NR_fcntl64            221
-# define __NR_gettid             224
 # define __NR_futex              240
 # define __NR_exit_group         248
 # define __NR_clock_gettime      263
 # define __NR_clock_getres       264
-# define __NR_tgkill             268
 # define __NR_utimes             271
 # define __NR_socketpair         288
 # define __NR_shutdown           293
 # define __NR_sendmsg            296
 # define __NR_recvmsg            297
 # define __NR_openat             322
 # define __NR_fstatat64          327
 # define __NR_ARM_cacheflush     0xf0002
 # define __NR_ARM_set_tls        0xf0005
 
 #else
 # error Unsupported architecture
 #endif
 
 #endif