-Fast bot fixes for AVX+ code

  1) Replace a couple commas with semicolons.
  2) Make sure to zero a couple vectors.

1) has no effect on code generation.
2) does add a bunch of self-vxorps, but they're cheap and we already do
the equivalent for <AVX SSE code, and they're in not very
performance-critical routines.  We could circle back and guard these
with !defined(JUMPER_IS_OFFLINE) if we really need the vectors to start
uninitialized for speed.

CQ_INCLUDE_TRYBOTS=skia.primary:Build-Debian9-Clang-x86_64-Release-Fast

Change-Id: I1a13f3eb28d664dbc345d71c3adbc62be5ff7c45
Reviewed-on: https://skia-review.googlesource.com/39661
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>
3 files changed