arm: Use <arm_neon.h> when compiling aarch64 intrinsics with clang-cl

MSVC's <arm64_neon.h> header contains cl.exe intrinsics that are not
recognized by clang-cl.

Contributed-by: Ryan VanderMeulen <rvandermeulen@mozilla.com>
Contributed-by: Mike Klein <mtklein@google.com>
Signed-off-by: Cosmin Truta <ctruta@gmail.com>
3 files changed