Fix build with clang https://bugs.gentoo.org/739144

Fixed upstream in: https://github.com/TASVideos/desmume/commit/92cb90f
--- a/desmume/src/texcache.cpp
+++ b/desmume/src/texcache.cpp
@@ -1165,8 +1165,8 @@ void NDSTextureUnpack4x4(const size_t sr
 	
 	for (size_t y = 0, d = 0; y < yTmpSize; y++)
 	{
-		u32 tmpPos[4]={(y<<2)*sizeX,((y<<2)+1)*sizeX,
-			((y<<2)+2)*sizeX,((y<<2)+3)*sizeX};
+		u32 tmpPos[4]={u32(y<<2)*sizeX,u32((y<<2)+1)*sizeX,
+			u32((y<<2)+2)*sizeX,u32((y<<2)+3)*sizeX};
 		for (size_t x = 0; x < xTmpSize; x++, d++)
 		{
 			if (d >= limit)