configure: If cross-compiling, assume we have working semaphores

The Asterisk 13 configure.ac checks for HAS_WORKING_SEMAPHORE but does not have
an option for cross-compiling so it fails with an exit. Since we're cross-
compiling, we can't exactly go looking for the header. The semaphore.h header
is relatively common:
* It's part of the POSIX standard
* It's part of GNU C Library
As such, we assume that it will be present when cross-compiling.

As such, this patch defaults "HAS_WORKING_SEMAPHORE" to "1" if cross-compiling
is detected.

If you're cross-compiling to a platform that doesn't support this, then make
sure you re-define this to 0.

ASTERISK-24663 #close
Reported by: abelbeck
patches:
  asterisk-13-anonymous-semaphores.patch uploaded by abelbeck (License 5903)
........

Merged revisions 430646 from http://svn.asterisk.org/svn/asterisk/branches/13


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@430647 65c4cc65-6c06-0410-ace0-fbb531ad65f3

configure

@@ -1,5 +1,5 @@
 #! /bin/sh
-# From configure.ac Revision: 426235 .
+# From configure.ac Revision: 430547 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.69 for asterisk trunk.
 #
@@ -16073,10 +16073,14 @@ rm -f core conftest.err conftest.$ac_objext \
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for working unnamed semaphores" >&5
 $as_echo_n "checking for working unnamed semaphores... " >&6; }
 if test "$cross_compiling" = yes; then :
-  { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
-$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
-as_fn_error $? "cannot run test program while cross compiling
-See \`config.log' for more details" "$LINENO" 5; }
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: cross-compile" >&5
+$as_echo "cross-compile" >&6; }
+	{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: result yes guessed because of cross compilation" >&5
+$as_echo "$as_me: WARNING: result yes guessed because of cross compilation" >&6;}
+
+$as_echo "#define HAS_WORKING_SEMAPHORE 1" >>confdefs.h
+
+
 else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
@@ -16098,7 +16102,6 @@ $as_echo "#define HAS_WORKING_SEMAPHORE 1" >>confdefs.h
 else
   { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
 $as_echo "no" >&6; }
-
 fi
 rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
   conftest.$ac_objext conftest.beam conftest.$ac_ext

configure.ac

@@ -884,7 +884,10 @@ AC_RUN_IFELSE(
 		[sem_t sem; return sem_init(&sem, 0, 0);])],
 	AC_MSG_RESULT(yes)
 	AC_DEFINE([HAS_WORKING_SEMAPHORE], 1, [Define to 1 if anonymous semaphores work.]),
-	AC_MSG_RESULT(no)
+	AC_MSG_RESULT(no),
+	AC_MSG_RESULT(cross-compile)
+	AC_MSG_NOTICE([WARNING: result yes guessed because of cross compilation])
+	AC_DEFINE([HAS_WORKING_SEMAPHORE], 1, [Define to 1 if anonymous semaphores work.])
 )
 
 LIBS="$save_LIBS"