Quickfix: Add Linux compiler hint for MESA bug

See issue PascalGameDevelopment#56.

Author: Free-Pascal-meets-SDL-Website

units/sdl2.pas

@@ -134,6 +134,8 @@ interface
       {$ELSE}
         SDL_LibName = 'libSDL2.so.0';
       {$ENDIF}
+      {$HINT Known MESA bug generating float-point exception in software graphics mode!
+             See https://github.com/PascalGameDevelopment/SDL2-for-Pascal/issues/56 for reference.}
     {$ENDIF}
   {$ENDIF}