wireguard: bump to 0.0.20181006

wireguard: bump to 0.0.20181006

* Account for big-endian 2^26 conversion in Poly1305.
  * Account for big-endian NEON in Curve25519.
  * Fix macros in big-endian AArch64 code so that this will actually run there
    at all.
  * Prefer if (IS_ENABLED(...)) over ifdef mazes when possible.
  * Call simd_relax() within any preempt-disabling glue code every once in a
    while so as not to increase latency if folks pass in super long buffers.
  * Prefer compiler-defined architecture macros in assembly code, which puts us
    in closer alignment with upstream CRYPTOGAMS code, and is cleaner.
  * Non-static symbols are prefixed with wg_ to avoid polluting the global
    namespace.
  * Return a bool from simd_relax() indicating whether or not we were
    rescheduled.
  * Reflect the proper simd conditions on arm.
  * Do not reorder lines in Kbuild files for the simd asm-generic addition,
    since we don't want to cause merge conflicts.
  * WARN() if the selftests fail in Zinc, since if this is an initcall, it won't
    block module loading, so we want to be loud.
  * Document some interdependencies beside include statements.
  * Add missing static statement to fpu init functions.
  * Use union in chacha to access state words as a flat matrix, instead of
    casting a struct to a u8 and hoping all goes well. Then, by passing around
    that array as a struct for as long as possible, we can update counter[0]
    instead of state[12] in the generic blocks, which makes it clearer what's
    happening.
  * Remove __aligned(32) for chacha20_ctx since we no longer use vmovdqa on x86,
    and the other implementations do not require that kind of alignment either.
  * Submit patch to ARM tree for adjusting RiscPC's cflags to be -march=armv3 so
    that we can build code that uses umull.
  * Allow CONFIG_ARM[64] to imply [!]CONFIG_64BIT, and use zinc arch config
    variables consistently throughout.
  * Document rationale for the 2^26->2^64/32 conversion in code comments.
  * Convert all of remaining BUG_ON to WARN_ON.
  * Replace `bxeq lr` with `reteq lr` in ARM assembler to be compatible with old
    ISAs via the macro in <asm/assembler.h>.
  * Do not allow WireGuard to be a built-in if IPv6 is a module.
  * Writeback the base register and reorder multiplications in the NEON x25519
    implementation.
  * Try all combinations of different implementations in selftests, so that
    potential bugs are more immediately unearthed.
  * Self tests and SIMD glue code work with #include, which lets the compiler
    optimize these. Previously these files were .h, because they were included,
    but a simple grep of the kernel tree shows 259 other files that carry out
    this same pattern. Only they prefer to instead name the files with a .c
    instead of a .h, so we now follow the convention.
  * Support many more platforms in QEMU, especially big endian ones.
  * Kernels < 3.17 don't have read_cpuid_part, so fix building there.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>