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>

 # ltrace

 ## depends on ! BACKEND

 ##

 ## select LIBELF_TARGET

 ##

 ## help ltrace is a program that simply runs the specified command until it exits.

 ## help It intercepts and records the dynamic library calls which are called by

 ## help the executed process and the signals which are received by that process.

 ## help It can also intercept and print the system calls executed by the program.

 choice

     bool

     prompt "ltrace version"

 # Don't remove next line

 # CT_INSERT_VERSION_BELOW

 config LTRACE_V_0_5_3

     bool

     prompt "0.5.3"

     select LTRACE_0_5_3_or_later

 config LTRACE_V_0_5_2

     bool

     prompt "0.5.2"

 config LTRACE_V_0_5

     bool

     prompt "0.5 (OBSOLETE)"

     depends on OBSOLETE

 config LTRACE_V_0_4

     bool

     prompt "0.4 (OBSOLETE)"

     depends on OBSOLETE

 endchoice

 config LTRACE_VERSION

     string

 # Don't remove next line

 # CT_INSERT_VERSION_STRING_BELOW

     default "0.5.3" if LTRACE_V_0_5_3

     default "0.5.2" if LTRACE_V_0_5_2

     default "0.5.1" if LTRACE_V_0_5_1

     default "0.5" if LTRACE_V_0_5

     default "0.4" if LTRACE_V_0_4

 config LTRACE_0_5_3_or_later

     bool