Add -lpthread flag.


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3538 c046a42c-6fe2-441c-8c8c-71466251a162
diff --git a/configure b/configure
index c8a78b9..8eb4e74 100755
--- a/configure
+++ b/configure
@@ -312,7 +312,8 @@
 if [ "$bsd" = "yes" -o "$darwin" = "yes" -o "$mingw32" = "yes" ] ; then
     AIOLIBS=
 else
-    AIOLIBS="-lrt"
+    # Some Linux architectures (e.g. s390) don't imply -lpthread automatically.
+    AIOLIBS="-lrt -lpthread"
 fi
 
 # default flags for all hosts