Change algorithm to work on 64-bit integers rather than 32-bit integers internally

core/math/rand/system_darwin.odin

@@ -3,10 +3,10 @@ package rand
 import "core:sys/darwin"
 
 @(require_results)
-_system_random :: proc() -> u32 {
+_system_random :: proc() -> u64 {
 	for {
-		value: u32
-		ret := darwin.syscall_getentropy(([^]u8)(&value), 4)
+		value: u64
+		ret := darwin.syscall_getentropy(([^]u8)(&value), size_of(value))
 		if ret < 0 {
 			switch ret {
 			case -4: // EINTR