[PATCH] libsanitizer: Avoid implicit function declaration in configure test

[Florian Weimer via Gcc-patches]

libsanitizer/

        * configure.ac (check for necessary platform features):
        Include <unistd.h> for syscall prototype.
        * configure: Regenerate.

---
 libsanitizer/configure    | 5 +++--
 libsanitizer/configure.ac | 3 ++-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/libsanitizer/configure b/libsanitizer/configure
index 3a0c47513e7..cb99faf6100 100755
--- a/libsanitizer/configure
+++ b/libsanitizer/configure
@@ -12383,7 +12383,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 12386 "configure"
+#line 12398 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -12489,7 +12489,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 12492 "configure"
+#line 12504 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -16072,6 +16072,7 @@ case "$target" in
     cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 #include <sys/syscall.h>
+#include <unistd.h>
 int
 main ()
 {
diff --git a/libsanitizer/configure.ac b/libsanitizer/configure.ac
index 7f1ef3979c4..ad49f29db7e 100644
--- a/libsanitizer/configure.ac
+++ b/libsanitizer/configure.ac
@@ -161,7 +161,8 @@ case "$target" in
   *-*-linux*)
     # Some old Linux distributions miss required syscalls.
     sanitizer_supported=no
-    AC_TRY_COMPILE([#include <sys/syscall.h>],[
+    AC_TRY_COMPILE([#include <sys/syscall.h>
+#include <unistd.h>],[
       syscall (__NR_gettid);
       syscall (__NR_futex);
       syscall (__NR_exit_group);

base-commit: acdb24166d13d87c374e578d2ad5d58249171930