This is a backport of this patch from 6.5 to 4.9:

  https://gcc.gnu.org/git/?p=gcc.git;a=patch;h=8937b94d1a643fd9760714642296d034a45254a8

diff --git a/libsanitizer/sanitizer_common/sanitizer_linux.cc b/libsanitizer/sanitizer_common/sanitizer_linux.cc
index 69c9c10..8e53673 100644
--- a/libsanitizer/sanitizer_common/sanitizer_linux.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_linux.cc
@@ -599,8 +599,7 @@ uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5) {
   return internal_syscall(__NR_prctl, option, arg2, arg3, arg4, arg5);
 }
 
-uptr internal_sigaltstack(const struct sigaltstack *ss,
-                         struct sigaltstack *oss) {
+uptr internal_sigaltstack(const void *ss, void *oss) {
   return internal_syscall(__NR_sigaltstack, (uptr)ss, (uptr)oss);
 }
 
diff --git a/libsanitizer/sanitizer_common/sanitizer_linux.h b/libsanitizer/sanitizer_common/sanitizer_linux.h
index 6422df1..8a8e526 100644
--- a/libsanitizer/sanitizer_common/sanitizer_linux.h
+++ b/libsanitizer/sanitizer_common/sanitizer_linux.h
@@ -18,7 +18,6 @@
 #include "sanitizer_platform_limits_posix.h"
 
 struct link_map;  // Opaque type returned by dlopen().
-struct sigaltstack;
 
 namespace __sanitizer {
 // Dirent structure for getdents(). Note that this structure is different from
@@ -28,8 +27,7 @@ struct linux_dirent;
 // Syscall wrappers.
 uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count);
 uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5);
-uptr internal_sigaltstack(const struct sigaltstack* ss,
-                          struct sigaltstack* oss);
+uptr internal_sigaltstack(const void *ss, void *oss);
 uptr internal_sigaction(int signum, const __sanitizer_kernel_sigaction_t *act,
     __sanitizer_kernel_sigaction_t *oldact);
 uptr internal_sigprocmask(int how, __sanitizer_kernel_sigset_t *set,
diff --git a/libsanitizer/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc b/libsanitizer/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc
index 6ee63ec..50c21a3 100644
--- a/libsanitizer/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc
@@ -238,7 +238,7 @@ static int TracerThread(void* argument) {
 
   // Alternate stack for signal handling.
   InternalScopedBuffer<char> handler_stack_memory(kHandlerStackSize);
-  struct sigaltstack handler_stack;
+  stack_t handler_stack;
   internal_memset(&handler_stack, 0, sizeof(handler_stack));
   handler_stack.ss_sp = handler_stack_memory.data();
   handler_stack.ss_size = kHandlerStackSize;
diff --git a/libsanitizer/tsan/tsan_platform_linux.cc b/libsanitizer/tsan/tsan_platform_linux.cc
index fe69430..49f5270 100644
--- a/libsanitizer/tsan/tsan_platform_linux.cc
+++ b/libsanitizer/tsan/tsan_platform_linux.cc
@@ -351,7 +351,7 @@ bool IsGlobalVar(uptr addr) {
 // closes within glibc. The code is a pure hack.
 int ExtractResolvFDs(void *state, int *fds, int nfd) {
   int cnt = 0;
-  __res_state *statp = (__res_state*)state;
+  struct __res_state *statp = (struct __res_state*)state;
   for (int i = 0; i < MAXNS && cnt < nfd; i++) {
     if (statp->_u._ext.nsaddrs[i] && statp->_u._ext.nssocks[i] != -1)
       fds[cnt++] = statp->_u._ext.nssocks[i];
cts for package ones.
* gnu/services/cgit.scm (cgit-configuration, opaque-cgit-configuration):
Likewise.
* gnu/services/cups.scm (package-list?, cups-configuration): Likewise.
* gnu/services/dns.scm (verify-knot-configuration)
(ddclient-configuration): Likewise.
* gnu/services/docker.scm (docker-configuration): Likewise.
* gnu/services/file-sharing.scm (transmission-daemon-configuration): Likewise.
* gnu/services/getmail.scm (getmail-configuration): Likewise.
* gnu/services/mail.scm (dovecot-configuration)
(opaque-dovecot-configuration): Likewise.
* gnu/services/messaging.scm (prosody-configuration)
(opaque-prosody-configuration): Likewise.
* gnu/services/monitoring.scm (zabbix-server-configuration)
(zabbix-agent-configuration): Likewise.
* gnu/services/networking.scm (opendht-configuration): Likewise.
* gnu/services/pm.scm (tlp-configuration): Likewise.
* gnu/services/telephony.scm (jami-configuration): Likewise.
* gnu/services/virtualization.scm (libvirt-configuration)
(qemu-guest-agent-configuration): Likewise.
* gnu/services/vpn.scm (openvpn-client-configuration): Likewise.


</td></tr>
<tr class='logheader'><td><span title='2020-06-13 10:04:51 +0200'>2020-06-13</span></td><td class='logsubject'><a href='/guix/commit/gnu/services/hurd.scm?id=7304cb0a23a11b68d98ee70d911adc7048900536'>services: hurd: Remove deprecated 'hurd-getty-service' wrapper.</a></td><td>Jan (janneke) Nieuwenhuizen</td></tr>
<tr class='nohover-highlight'><td/><td colspan='3' class='logmsg'>
* gnu/services/hurd.scm (hurd-getty-service): Remove.


</td></tr>
<tr class='logheader'><td><span title='2020-06-08 14:26:14 +0200'>2020-06-08</span></td><td class='logsubject'><a href='/guix/commit/gnu/services/hurd.scm?id=7ccd471c71d650055e99cd02381bc8dcd86d5313'>services: Add `hurd-getty-service-type'.</a></td><td>Jan (janneke) Nieuwenhuizen</td></tr>
<tr class='nohover-highlight'><td/><td colspan='3' class='logmsg'>
* gnu/services/hurd.scm (&lt;hurd-gettty-configuration&gt;): New record.
(hurd-ttys-shepherd-service): New procedure.
(hurd-getty-service-type): New variable.
* doc/guix.texi (Hurd Services): Document it.


</td></tr>
<tr class='logheader'><td><span title='2020-06-08 14:26:14 +0200'>2020-06-08</span></td><td class='logsubject'><a href='/guix/commit/gnu/services/hurd.scm?id=f9c04580bf5462bb088f47ad8fc6c3136649cbd6'>services: Add `hurd-console-service-type'.</a></td><td>Jan (janneke) Nieuwenhuizen</td></tr>
<tr class='nohover-highlight'><td/><td colspan='3' class='logmsg'>
* gnu/services/hurd.scm: New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add it.
* doc/guix.texi (Hurd Services): Document it.


</td></tr>