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>

diff -durN gcc-4.4.0.orig/gcc/builtins.c gcc-4.4.0/gcc/builtins.c

--- gcc-4.4.0.orig/gcc/builtins.c	2009-03-30 19:42:27.000000000 +0200

+++ gcc-4.4.0/gcc/builtins.c	2009-05-27 21:38:01.000000000 +0200

@@ -5768,6 +5768,9 @@

   trampolines_created = 1;

   INITIALIZE_TRAMPOLINE (r_tramp, r_func, r_chain);

+  if (warn_trampolines)

+    warning (OPT_Wtrampolines, "generating trampoline in object (requires executable stack)");

+

   return const0_rtx;

 }

diff -durN gcc-4.4.0.orig/gcc/common.opt gcc-4.4.0/gcc/common.opt

--- gcc-4.4.0.orig/gcc/common.opt	2009-03-28 18:28:45.000000000 +0100

+++ gcc-4.4.0/gcc/common.opt	2009-05-27 21:38:01.000000000 +0200

@@ -197,6 +197,10 @@

 Common Var(warn_type_limits) Init(-1) Warning

 Warn if a comparison is always true or always false due to the limited range of the data type

+Wtrampolines

+Common Var(warn_trampolines) Init(1)

+Warn whenever a trampoline is generated

+

 Wuninitialized

 Common Var(warn_uninitialized) Warning

 Warn about uninitialized automatic variables