complibs/ppl: build watchdog library

gcc-4.6+ requires the Parma Watchdog Library (libpwl).
Build it and use it.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

scripts/build/companion_libs/ppl.sh

@@ -48,6 +48,8 @@ do_ppl() {
         --prefix="${CT_COMPLIBS_DIR}"               \
         --with-libgmp-prefix="${CT_COMPLIBS_DIR}"   \
         --with-libgmpxx-prefix="${CT_COMPLIBS_DIR}" \
+        --enable-cxx                                \
+        --enable-watchdog                           \
         --disable-debugging                         \
         --disable-assertions                        \
         --disable-ppl_lcdd                          \