fixed Xcode compile error

tools/shaderc/shaderc_spirv.cpp

@@ -14,6 +14,7 @@ BX_PRAGMA_DIAGNOSTIC_IGNORED_CLANG_GCC("-Wshadow") // warning: declaration of 'u
 #include <ResourceLimits.h>
 #include <SPIRV/SPVRemapper.h>
 #include <SPIRV/GlslangToSpv.h>
+#define SPIRV_CROSS_EXCEPTIONS_TO_ASSERTIONS
 #include <spirv_msl.hpp>
 BX_PRAGMA_DIAGNOSTIC_POP()