DBusBasicValue: add bool_val and fd members to complete the set

dbus_bool_t is the same as dbus_uint32_t, but if we have a separate
bool_val member, it's more obvious that people are getting it right.
It's not called bool because that's a keyword in C++.

int (for file descriptors) doesn't appear in the D-Bus message wire
format, but then again neither does char *, and
dbus_message_iter_get_basic() and friends can return an int (due to
internal index-into-array-of-fds -> fd remapping in libdbus).
In theory int might not be the same size as any of the dbus_intNN_t
types, and anyway it's easier to see that people are getting it right
if we make it explicit.

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=11191
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: Will Thompson <will.thompson@collabora.co.uk>

dbus/dbus-types.h

@@ -161,6 +161,7 @@ typedef union
   dbus_uint16_t u16;   /**< as int16 */
   dbus_int32_t  i32;   /**< as int32 */
   dbus_uint32_t u32;   /**< as int32 */
+  dbus_bool_t   bool_val; /**< as boolean */
 #ifdef DBUS_HAVE_INT64
   dbus_int64_t  i64;   /**< as int64 */
   dbus_uint64_t u64;   /**< as int64 */
@@ -168,7 +169,8 @@ typedef union
   DBus8ByteStruct eight; /**< as 8-byte struct */
   double dbl;          /**< as double */
   unsigned char byt;   /**< as byte */
-  char *str;           /**< as char* */
+  char *str;           /**< as char* (string, object path or signature) */
+  int fd;              /**< as Unix file descriptor */
 } DBusBasicValue;
 
 /** @} */