add size.h and types.h

include/types/size.h

@@ -0,0 +1,6 @@
+#pragma once
+
+#include "stdint.h"
+
+typedef uint32_t ptr_t;
+typedef int32_t diff_t;

include/types/types.h

@@ -0,0 +1,4 @@
+#pragma once
+
+#include "size.h"
+#include "stdint.h"