complibs/cloog: fix linking with libm

In Ubuntu 11.04 and 11.10, the default options for ld have changed.
--no-copy-dt-needed-entries and --as-needed are now enabled by default, which
causes errors like:

[EXTRA] Checking CLooG/ppl
[DEBUG] ==> Executing: 'make' '-j3' '-s' 'check'
[ALL ] Making check in .
[ALL ] config.status: creating include/cloog/cloog-config.h
[ALL ] config.status: include/cloog/cloog-config.h is unchanged
[ALL ] libtool: link: i686-build_pc-linux-gnu-gcc -Wall -fomit-frame-pointer
-pipe -o cloog cloog.o -L/<snip>/build/static/lib ./.libs/libcloog.a -lm
/<snip>/build/static/lib/libppl_c.a /<snip>/build/static/lib/libpwl.a
/<snip>/build/static/lib/libppl.a /<snip>/build/static/lib/libgmpxx.a
/<snip>/build/static/lib/libgmp.a -lstdc++
[ALL ] /usr/bin/ld: /<snip>/build/static/lib/libppl.a(MIP_Problem.o):
undefined reference to symbol 'sqrt@@GLIBC_2.0'
[ALL ] /usr/bin/ld: note: 'sqrt@@GLIBC_2.0' is defined in DSO
/usr/lib/gcc/i686-linux-gnu/4.6.1/../../../i386-linux-gnu/libm.so so try adding
it to the linker command line
[ALL ] /usr/lib/gcc/i686-linux-gnu/4.6.1/../../../i386-linux-gnu/libm.so:
could not read symbols: Invalid operation
[ALL ] collect2: ld returned 1 exit status
[ERROR] make[2]: *** [cloog] Error 1
[ERROR] make[1]: *** [check-recursive] Error 1

See:
https://wiki.ubuntu.com/NattyNarwhal/ToolchainTransition

This patch fixes these errors by placing '-lm' at the right place on the command
line as libppl requires libm when linking cloog.

Signed-off-by: "Benoît Thébaudeau" <benoit.thebaudeau@advansee.com>

 Original patch from: gentoo/src/patchsets/glibc/2.9/0051_all_glibc-2.9-add_prio-macros.patch

 -= BEGIN original header =-

 http://sourceware.org/ml/libc-alpha/2009-01/msg00003.html

 From a1737958e074e8f990760acc8abeb0c23715a859 Mon Sep 17 00:00:00 2001

 From: Roland McGrath <roland@gnu.org>

 Date: Sat, 3 Jan 2009 21:04:01 +0000

 Subject: [PATCH] 2009-01-03  Samuel Thibault  <samuel.thibault@ens-lyon.org>

 	* bits/resource.h (PRIO_PROCESS, PRIO_PGRP, PRIO_USER): Add macros.

 -= END original header =-

 diff -durN glibc-2_9.orig/bits/resource.h glibc-2_9/bits/resource.h

 --- glibc-2_9.orig/bits/resource.h	2006-03-05 23:48:10.000000000 +0100

 +++ glibc-2_9/bits/resource.h	2009-02-02 22:00:38.000000000 +0100

 @@ -185,6 +185,9 @@

  enum __priority_which

    {

      PRIO_PROCESS = 0,           /* WHO is a process ID.  */

 +#define PRIO_PROCESS PRIO_PROCESS

      PRIO_PGRP = 1,              /* WHO is a process group ID.  */

 +#define PRIO_PGRP PRIO_PGRP

      PRIO_USER = 2               /* WHO is a user ID.  */

 +#define PRIO_USER PRIO_USER

    };