Explicitly include cstdint in the AAL.

This is not necessary with libc++ platforms because of some header
pollution, but is necessary everywhere else.

src/aal/aal.h

@@ -1,6 +1,8 @@
 #pragma once
 #include "ds/defines.h"
 
+#include <cstdint>
+
 #if defined(__i386__) || defined(_M_IX86) || defined(_X86_) || \
   defined(__amd64__) || defined(__x86_64__) || defined(_M_X64) || \
   defined(_M_AMD64)