wireguard: bump to 0.0.20181115

wireguard: bump to 0.0.20181115

* Zinc no longer ships generated assembly code. Rather, we now
  bundle in the original perlasm generator for it. The primary purpose
  of this snapshot is to get testing of this.
* Clarify the peer removal logic and make lifetimes more precise.
* Use READ_ONCE for is_valid and is_dead.
* No need to use atomic when the recounter is mutex protected.
* Fix up macros and annotations in allowedips.
* Increment drop counter when staged packets are dropped.
* Use static constants instead of enums for 64-bit values in selftest.
* Mark large constants as ULL in poly1305-donna64.
* Fix sparse warnings in allowedips debugging code.
* Do not use wg_peer_get_maybe_zero in timer callbacks, since we now can
  carefully control the lifetime of these functions and ensure they never
  execute after dropping the last reference.
* Cleanup hashing in ratelimiter.
* Do not guard timer removals, since del_timer is always okay.
* We now check for PM_AUTOSLEEP, which makes the clear*on-suspend decision a
  bit more general.
* Set csum_level to ~0, since the poly1305 authenticator certainly means
  that no data was modified in transit.
* Use CHECKSUM_PARTIAL check for skb_checksum_help instead of
  skb_checksum_setup check.
* wg.8: specify that wg(8) shows runtime info too
* wg.8: AllowedIPs isn't actually required
* keygen-html: add missing glue macro
* wg-quick: android: do not choke on empty allowed-ips

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
(backported from bf52c968e863768494e79731550c62610dd3cf78)