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>

 do not bother running ldconfig on DESTDIR.  it wants to write the temp cache

 file outside of the chroot.  doesnt matter anyways as we wont use the cache

 results (portage will rebuild cache), so running ldconfig is simply a waste

 of time.

 diff -durN glibc-2.12.1.orig/Makefile glibc-2.12.1/Makefile

 --- glibc-2.12.1.orig/Makefile	2009-04-23 20:23:03.000000000 +0200

 +++ glibc-2.12.1/Makefile	2009-11-13 00:49:49.000000000 +0100

 @@ -116,6 +116,7 @@

  	rm -f $(symbolic-link-list)

  install:

 +dont-bother-with-destdir:

  	-test ! -x $(common-objpfx)elf/ldconfig || LC_ALL=C LANGUAGE=C \

  	  $(common-objpfx)elf/ldconfig $(addprefix -r ,$(install_root)) \

  				       $(slibdir) $(libdir)