Move libultra function declarations to libultra headers (#1196)

* Delete unused headers

* Move PR and io to ultra64

* move headers to ultra64

* more cleanups

* more reorganizing

* i think that should be all

* format

* ifdef guards cleanup

* Add IO_READ and IO_WRITE macros for future use

* warnings

* review

Co-authored-by: Tharo <17233964+Thar0@users.noreply.github.com>

* warnings again

* warn

* ifdef guards

* fix merge

* fix merge

* fix merge

* bss

* padutils.h

* bss

* bss

* bss

* fix merge

* bss

* bss

* bss

* fix merge

* fixes

* fixes

* bss

* bss

* fix merge

* fix

* fix

* fix includepaths

* fix paths

* bss

* fix

* ultra64/ -> PR/

* header guards

* fix ehader guards

* fix

* fix++

* format

* bss is borken

* prevent 2

* :despair:

* bss

* rename assert to dbg_hungup

* fix

* a

* fix

* bss

* fix

* bss

* bss

---------

Co-authored-by: Tharo <17233964+Thar0@users.noreply.github.com>

include/libc/stdlib.h

@@ -1,5 +1,5 @@
-#ifndef STDLIB_H
-#define STDLIB_H
+#ifndef LIBC_STDLIB_H
+#define LIBC_STDLIB_H
 
 #include "libc/stddef.h"
 
@@ -22,4 +22,7 @@ typedef int ssize_t;
 
 typedef long wchar_t;
 
+ldiv_t ldiv(long numer, long denom);
+lldiv_t lldiv(long long numer, long long denom);
+
 #endif /* STDLIB_H */