3373 gcc >= 4.5 concerns about offsetof()

*** 48,58 ****
--- 48,62 ----
  /* For logging. */
  #define UWBA_LOG_DEBUG          2
  #define UWBA_LOG_LOG            1
  #define UWBA_LOG_CONSOLE        0
  
+ #if defined(__GNUC__)
+ #define offsetof(s, m)  __builtin_offsetof(s, m)
+ #else
  #define offsetof(s, m)  ((size_t)(&(((s *)0)->m)))
+ #endif
  #define isdigit(ch) ((ch >= '0') && (ch <= '9'))
  
  #define UWB_RAW_RESULT_CODE_SIZE        5  /* size of RCEB + bResultCode */
  #define UWB_RAW_RCCB_HEAD_SIZE          4  /* size of RCCB */