Added AC_LANG_SOURCE() invocations where appropriate.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@11628 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/configure.in b/configure.in
index 49488f4..92f4696 100644
--- a/configure.in
+++ b/configure.in
@@ -1780,8 +1780,7 @@
 safe_CXXFLAGS=$CXXFLAGS
 CXXFLAGS="-lboost_thread-mt $mflag_primary"
 
-AC_LINK_IFELSE(
-[
+AC_LINK_IFELSE([AC_LANG_SOURCE([
 #include <boost/thread.hpp>
 static void thread_func(void)
 { }
@@ -1790,7 +1789,7 @@
   boost::thread t(thread_func);
   return 0;
 }
-],
+])],
 [
 ac_have_boost_1_35=yes
 AC_SUBST([BOOST_CFLAGS], [])
@@ -1815,15 +1814,14 @@
 safe_CFLAGS=$CFLAGS
 CFLAGS="-fopenmp $mflag_primary"
 
-AC_LINK_IFELSE(
-[
+AC_LINK_IFELSE([AC_LANG_SOURCE([
 #include <omp.h> 
 int main(int argc, char** argv)
 {
   omp_set_dynamic(0);
   return 0;
 }
-],
+])],
 [
 ac_have_openmp=yes
 AC_MSG_RESULT([yes])