VFS: Use smaller numbers as file descriptors

components/newlib/include/sys/types.h

@@ -221,9 +221,6 @@ typedef unsigned int mode_t _ST_INT32;
 
 typedef unsigned short nlink_t;
 
-/* FD_SET and friends are still LWIP only */
-# if !defined(ESP_PLATFORM)
-
 /* We don't define fd_set and friends if we are compiling POSIX
    source, or if we have included (or may include as indicated
    by __USE_W32_SOCKETS) the W32api winsock[2].h header which
@@ -269,7 +266,6 @@ typedef	struct _types_fd_set {
 }))
 
 # endif	/* !(defined (_POSIX_SOURCE) || defined (_WINSOCK_H) || defined (_WINSOCKAPI_) || defined (__USE_W32_SOCKETS)) */
-#endif /* !defined(ESP_PLATFORM) */
 
 #undef __MS_types__
 #undef _ST_INT32