Treat MagnumMathObjects and MagnumObjects libs separately for exporting.

It's more intuitive and might be useful at some point.

src/CMakeLists.txt

@@ -156,7 +156,8 @@ set(MagnumMath_SRCS
 # TODO: fix when CMake sets target_EXPORTS for OBJECT targets as well
 add_library(MagnumMathObjects OBJECT ${MagnumMath_SRCS})
 add_library(MagnumObjects OBJECT ${Magnum_SRCS})
-set_target_properties(MagnumObjects MagnumMathObjects PROPERTIES COMPILE_FLAGS "-DMagnumObjects_EXPORTS ${CMAKE_SHARED_LIBRARY_CXX_FLAGS}")
+set_target_properties(MagnumMathObjects PROPERTIES COMPILE_FLAGS "-DMagnumMathObjects_EXPORTS ${CMAKE_SHARED_LIBRARY_CXX_FLAGS}")
+set_target_properties(MagnumObjects PROPERTIES COMPILE_FLAGS "-DMagnumObjects_EXPORTS ${CMAKE_SHARED_LIBRARY_CXX_FLAGS}")
 
 # Main library
 add_library(Magnum ${SHARED_OR_STATIC}

src/magnumVisibility.h

@@ -26,7 +26,7 @@
 
 #include <Utility/Visibility.h>
 
-#if defined(Magnum_EXPORTS) || defined(MagnumObjects_EXPORTS)
+#if defined(Magnum_EXPORTS) || defined(MagnumObjects_EXPORTS) || defined(MagnumMathObjects_EXPORTS)
     #define MAGNUM_EXPORT CORRADE_VISIBILITY_EXPORT
 #else
     #define MAGNUM_EXPORT CORRADE_VISIBILITY_IMPORT