improve perf
add arm32/64 code for InitHash
Add ifdef HAVE_NEON around the contents of arm_arch_common_macro.S

This file is built on its own from within the xcode projects,
even though it isn't necessary. Previously its contents was just
empty, but now a .syntax unified was added, which failed the build
when building for arm64.

Make this file a no-op, just like the other arm assembly source files,
unless HAVE_NEON is defined.
Merge pull request #1279 from dongzha/NewAddARMHash

add arm32/64 code for InitHash
Merge pull request #1278 from syureyi/perf

improve perf
Merge pull request #1280 from mstorsjo/arm-common-ifdefs

Add ifdef HAVE_NEON around the contents of arm_arch_common_macro.S
Fix building svc_motion_estimation.S for android

The .align directive takes an argument in number of bits, i.e. the
actual alignment is 2^n. Previously building with binutils failed,
since 16 isn't a valid parameter to .align, the maximum is 15.

Thus, this makes the code try to align to 16 bytes, instead of aligning
to 65536 bytes.

This fixes building for android.

This also clears up the same mistake in the aarch64 code, even though
that one built just fine.
Merge pull request #1281 from mstorsjo/fix-arm-alignment

Fix building svc_motion_estimation.S for android
Merge remote-tracking branch 'upstream/master' into travis.osx