Specifying any CFLAGS clobbers any that liboil's configure script would

naturally choose.  With only an effective -O0 gcc 4.0.1 doesn't produce
code as intented for copy_u8_altivec, causing liboil to fail at runtime.

Summary, liboil really needs -O2 (always).
Signed-off-by: David Flynn <davidf@rd.bbc.co.uk>
Signed-off-by: Felix Paul Kühne <fkuehne@videolan.org>

extras/contrib/src/Makefile

@@ -2428,7 +2428,7 @@ liboil: liboil-$(OIL_VERSION).tar.gz
 	patch -d liboil -p1 < Patches/liboil-noshared.patch
 
 .liboil: liboil
-	(cd $<; $(HOSTCC) ./configure $(HOSTCONF) --prefix=$(PREFIX) && make && make install)
+	(cd $<; $(HOSTCC) ./configure $(HOSTCONF) --prefix=$(PREFIX) CFLAGS="$(CFLAGS) -O2" && make && make install)
 	touch $@
 
 CLEAN_FILE += .liboil