[mutter/wip/lantw/wayland-on-freebsd: 8/9] configure: Don't declare functions in AC_TRY_LINK and AC_TRY_COMPILE

[Jonas Ådahl <jadahl src gnome org>]

commit 2316068327ad9ab94de0edf478007b04cbed34e5
Author: Ting-Wei Lan <lantw src gnome org>
Date:   Sat Jan 20 17:37:24 2018 +0800

    configure: Don't declare functions in AC_TRY_LINK and AC_TRY_COMPILE
    
    https://bugzilla.gnome.org/show_bug.cgi?id=792717

 clutter/configure.ac | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/clutter/configure.ac b/clutter/configure.ac
index 3c3d0c558..08b848d42 100644
--- a/clutter/configure.ac
+++ b/clutter/configure.ac
@@ -149,7 +149,7 @@ AC_ARG_ENABLE([Bsymbolic],
                 saved_LDFLAGS="${LDFLAGS}"
                 AC_MSG_CHECKING([for -Bsymbolic-functions linker flag])
                 LDFLAGS=-Wl,-Bsymbolic-functions
-                AC_TRY_LINK([], [int main (void) { return 0; }],
+                AC_TRY_LINK([], [return 0],
                             [
                               AC_MSG_RESULT([yes])
                               enable_Bsymbolic=yes
@@ -170,7 +170,7 @@ dnl on other compilers, check if we can do -fvisibility=hidden
 SAVED_CFLAGS="${CFLAGS}"
 CFLAGS="-fvisibility=hidden"
 AC_MSG_CHECKING([for -fvisibility=hidden compiler flag])
-AC_TRY_COMPILE([], [int main (void) { return 0; }],
+AC_TRY_COMPILE([], [return 0],
               AC_MSG_RESULT(yes)
               enable_fvisibility_hidden=yes,
               AC_MSG_RESULT(no)