Fixed CXX tests

test/core/core_force_arch_unknown.cpp

@@ -1,4 +1,6 @@
-#define GLM_FORCE_ARCH_UNKNOWN
+#ifndef GLM_FORCE_ARCH_UNKNOWN
+#	define GLM_FORCE_ARCH_UNKNOWN
+#endif
 
 #include <glm/glm.hpp>
 #include <glm/ext.hpp>

test/core/core_force_compiler_unknown.cpp

@@ -1,4 +1,6 @@
-#define GLM_FORCE_COMPILER_UNKNOWN
+#ifndef GLM_FORCE_COMPILER_UNKNOWN
+#	define GLM_FORCE_COMPILER_UNKNOWN
+#endif
 
 #include <glm/glm.hpp>
 #include <glm/ext.hpp>

test/core/core_force_platform_unknown.cpp

@@ -1,4 +1,6 @@
-#define GLM_FORCE_PLATFORM_UNKNOWN
+#ifndef GLM_FORCE_PLATFORM_UNKNOWN
+#	define GLM_FORCE_PLATFORM_UNKNOWN
+#endif
 
 #include <glm/glm.hpp>
 #include <glm/ext.hpp>