Add AVX/AVX2 support for runtime check

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1867193002
CQ_EXTRA_TRYBOTS=client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD-Trybot

Review URL: https://codereview.chromium.org/1867193002
diff --git a/AUTHORS b/AUTHORS
index 893569c..a6ade42 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -30,6 +30,7 @@
 Pavel Krajcevski <pavel@cs.unc.edu>
 Samsung <*@samsung.com>
 Samsung Open Source Group <*@osg.samsung.com>
+Sergey Melnikov <Melnikov.Sergey.V@gmail.com>
 Skia <*@skia.org>
 Skia Buildbots <skia.buildbots@gmail.com>
 Sony Mobile Communications Inc. <*@sonymobile.com>