message: allow adding member names to anonymous unions in structs
diff: #define RLM_API RLM_EXPORT
  #endif // __cplusplus
  +// Some platforms don't support anonymous unions in structs.
  +// RLM_NO_ANON_UNIONS allows definining a member name for unions in structs where
  +// RLM_ANON_UNION_MEMBER(name) is used.
  +#ifdef RLM_NO_ANON_UNIONS
  +#define RLM_ANON_UNION_MEMBER(name) name
  +#else
  +#define RLM_ANON_UNION_MEMBER(name)
  +#endif
  typedef struct shared_realm realm_t;
  typedef struct realm_schema realm_schema_t;
  @@ -152,7 +160,7 @@ typedef struct realm_value {
  realm_link_t link;
  char data[16];
  - };
  + } RLM_ANON_UNION_MEMBER(values);
  realm_value_type_e type;
  } realm_value_t;
  