update SDL_COMPOSE_ERROR macro for windows clang-cl

from a patchset by Vladislav Dmitrievich Turbanov:
#4062

Author: sezero

src/render/direct3d11/SDL_render_d3d11.c

@@ -54,7 +54,7 @@ extern ISwapChainBackgroundPanelNative * WINRT_GlobalSwapChainBackgroundPanelNat
 #endif  /* __WINRT__ */
 
 
-#ifdef _MSC_VER
+#if defined(_MSC_VER) && !defined(__clang__)
 #define SDL_COMPOSE_ERROR(str) __FUNCTION__ ", " str
 #else
 #define SDL_COMPOSE_ERROR(str) SDL_STRINGIFY_ARG(__FUNCTION__) ", " str