complibs/cloog: create missing m4 dir

Because we now patch configure.in and configure, the Makefile quicks
in a re-build rule as the source files are now more recent than the
bundled generated files, and that fails because the m4 directory
is missing, although on some systems where aclocal is not installed,
the re-build rule does nothing (except a warning).

Always create tht directory.

Reported-by: Per Arnold Blaasmo <per-arnold.blaasmo@atmel.com>
[Also thanks to Thomas De Schampheleire <patrickdepinguin@gmail.com>
for some digging works on this issue]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

Original patch from gentoo: gentoo/src/patchsets/gcc/4.3.1/uclibc/90_all_303-c99-complex-ugly-hack.patch

diff -durN gcc-4.3.1.orig/libstdc++-v3/configure gcc-4.3.1/libstdc++-v3/configure

--- gcc-4.3.1.orig/libstdc++-v3/configure	2008-06-10 14:58:43.000000000 +0200

+++ gcc-4.3.1/libstdc++-v3/configure	2008-06-10 14:58:58.000000000 +0200

@@ -39006,6 +39006,9 @@

 cat >>conftest.$ac_ext <<_ACEOF

 /* end confdefs.h.  */

 #include <complex.h>

+#ifdef __UCLIBC__

+#error ugly hack to make sure configure test fails here for cross until uClibc supports the complex funcs

+#endif

 int

 main ()

 {