- fix compile on vs2017, change pow2char to static

- include nullptr check for mapname in music.cpp

source/build/include/compat.h

@@ -1095,7 +1095,7 @@ CONSTEXPR size_t logbasenegative(T n)
 static CONSTEXPR const char pow2char[8] = {1,2,4,8,16,32,64,128u};
 #else
 // Revert the above to a real bit shift through some C++ operator magic. That saves me from reverting all the code that uses this construct.
-struct 
+static struct 
 {
 	constexpr uint8_t operator[](int index) const { return 1 << index; };
 } pow2char;

source/common/music/music.cpp

@@ -566,7 +566,7 @@ int Mus_Play(const char *mapname, const char *fn, bool loop)
 		return 0;
 	}
 	// A restart was requested. Ignore the music name being passed and just try tp restart what got here last.
-	if (*mapname == '*')
+	if (mapname && *mapname == '*')
 	{
 		mapname = lastMusicLevel.GetChars();
 		fn = lastMusic.GetChars();