Misc: Compiling under SDL2 uncovered a few issues unrelated to SDL itself

Change-Id: I625d5dd02d3f70bc6484a8641eafdaf13812f4a7

apps/playback.c

@@ -58,6 +58,10 @@
 #include "pcm_mixer.h"
 #endif
 
+#ifdef SIMULATOR
+#include <strings.h>
+#endif
+
 /* TODO: The audio thread really is doing multitasking of acting like a
          consumer and producer of tracks. It may be advantageous to better
          logically separate the two functions. I won't go that far just yet. */

firmware/asm/thread.h

@@ -46,6 +46,8 @@ struct regs
      * give a decent amount of space and hope for the best...
      * FIXME: this isn't a great solution. */
     #undef MINSIGSTKSZ
+    #endif
+    #ifndef MINSIGSTKSZ
       #define MINSIGSTKSZ 16384
     #endif
     /* MINSIGSTKSZ for the OS to deliver the signal + 0x3000 for us */

firmware/include/string-extra.h

@@ -30,7 +30,7 @@
 #include "memset16.h"
 
 #if defined(WIN32) || defined(APPLICATION) \
-        || defined(__PCTOOL__)
+        || defined(__PCTOOL__) || defined(SIMULATOR)
 #ifndef mempcpy
 #define mempcpy __builtin_mempcpy
 #endif