Changing order allows ACX_PHTREAD to find -lthread 
before trying to use -pthread

http://bugs.gentoo.org/show_bug.cgi?id=282426

--- m4/acx_pthread.m4
+++ m4/acx_pthread.m4
@@ -123,7 +123,7 @@
 # which indicates that we try without any flags at all, and "pthread-config"
 # which is a program returning the flags for the Pth emulation library.
 
-acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config"
+acx_pthread_flags="pthreads none -Kthread -kthread lthread pthread -pthread -pthreads -mthreads --thread-safe -mt pthread-config"
 
 # The ordering *is* (sometimes) important.  Some notes on the
 # individual items follow: