Add intptr_t and uintptr_t stubs

Author: lcartey

cpp/common/test/includes/standard-library/cstdint.h

@@ -15,5 +15,7 @@ typedef uint8_t uint_fast8_t;
 typedef uint16_t uint_fast16_t;
 typedef uint32_t uint_fast32_t;
 typedef uint64_t uint_fast64_t;
+typedef long intptr_t;
+typedef unsigned long uintptr_t;
 } // namespace std
 #endif // _GHLIBCPP_CSTDINT