Remove functions.h (#2501)

* split most of functions.h

* osdriverominit

* forgot include

* fix

* remove functions.h

* temporary fix for fix_bss

* fix bss

* revert fix_bss.py change

include/memory_utils.h

@@ -0,0 +1,9 @@
+#ifndef MEMORY_UTILS_H
+#define MEMORY_UTILS_H
+
+#include "ultra64.h"
+
+void* MemCpy(void* dest, const void* src, s32 len);
+void* MemSet(void* dest, s32 val, s32 len);
+
+#endif