Fixing weak alias detection for llvm based compilers

Signed-off-by: Rafaël Carré <funman@videolan.org>
(cherry picked from commit dbedba79)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

contrib/src/caca/caca-llvm-weak-alias.patch

+--- libcaca/caca/caca.h 2011-07-05 00:09:51.000000000 -0700
++++ libcaca.new/caca/caca.h 2011-07-05 00:10:10.000000000 -0700
+@@ -645,7 +645,7 @@
+ #       define CACA_DEPRECATED
+ #   endif
+ 
+-#   if defined __GNUC__ && __GNUC__ > 3
++#   if !(defined __APPLE__ && defined __llvm__) && defined __GNUC__ && __GNUC__ > 3
+ #       define CACA_ALIAS(x) __attribute__ ((weak, alias(#x)))
+ #   else
+ #       define CACA_ALIAS(x)

contrib/src/caca/rules.mak

@@ -17,6 +17,8 @@ caca: libcaca-$(CACA_VERSION).tar.gz .sum-caca
 ifdef HAVE_MACOSX
 	$(APPLY) $(SRC)/caca/caca-osx-sdkofourchoice.patch
 endif
+	$(APPLY) $(SRC)/caca/caca-llvm-weak-alias.patch
+
 ifdef HAVE_WIN32
 	$(APPLY) $(SRC)/caca/caca-win32-static.patch
 endif