boost: fix boost_system BOOST_ERROR_CODE_HEADER_ONLY breakage

Ugly hack in ExternalProject_liborcus.mk as apparently it fails with the
define on Windows, and without on MacOSX :(

Change-Id: If0b52825122edd956044f61d413c57a76f485101

external/boost/UnpackedTarball_boost.mk

@@ -110,6 +110,9 @@ boost_patches += w4702.patch.0
 boost_patches += ubsan.patch.0
 boost_patches += rtti.patch.0
 
+# 5.0 branch fix
+boost_patches += boost.system.error_code_header_only_fix.patch.1
+
 $(eval $(call gb_UnpackedTarball_UnpackedTarball,boost))
 
 $(eval $(call gb_UnpackedTarball_set_tarball,boost,$(BOOST_TARBALL)))

external/boost/boost.system.error_code_header_only_fix.patch.1

+bundled boost 1.55 error_code.cpp breaks when compiled with BOOST_ERROR_CODE_HEADER_ONLY
+
+--- boost/libs/system/src/error_code.cpp.orig	2015-09-08 16:37:11.595528207 +0200
++++ boost/libs/system/src/error_code.cpp	2015-09-08 16:39:12.696518815 +0200
+@@ -17,6 +17,10 @@
+ #define BOOST_SYSTEM_SOURCE 
+ 
+ #include <boost/system/config.hpp>
++
++#ifndef BOOST_ERROR_CODE_CPP
++#define BOOST_ERROR_CODE_CPP
++
+ #include <boost/system/error_code.hpp>
+ #include <boost/cerrno.hpp>
+ #include <vector>
+@@ -477,3 +480,5 @@
+ 
+   } // namespace system
+ } // namespace boost
++
++#endif // BOOST_ERROR_CODE_CPP

external/liborcus/ExternalProject_liborcus.mk

@@ -63,7 +63,7 @@ liborcus_CPPFLAGS+=-D_GLIBCXX_DEBUG
 endif
 endif
 
-liborcus_CXXFLAGS=$(CXXFLAGS) $(gb_VISIBILITY_FLAGS) $(gb_VISIBILITY_FLAGS_CXX) $(CXXFLAGS_CXX11) -DBOOST_SYSTEM_NO_DEPRECATED
+liborcus_CXXFLAGS=$(CXXFLAGS) $(gb_VISIBILITY_FLAGS) $(gb_VISIBILITY_FLAGS_CXX) $(CXXFLAGS_CXX11) -DBOOST_SYSTEM_NO_DEPRECATED $(if $(filter MACOSX,$(OS)),-DBOOST_ERROR_CODE_HEADER_ONLY)
 liborcus_LDFLAGS=$(LDFLAGS) $(gb_LTOFLAGS)
 ifeq ($(COM),MSC)
 liborcus_CXXFLAGS+=$(BOOST_CXXFLAGS)