aarch64: orcprogram-neon porting to aarch64

This PR ports orcprogram-neon.c for AArch64 support.
It makes the orc compiler generate aarch64 assembly codes.

Currently, example1 succesfully runs on aarch64 (tested on an Android device).

Signed-off-by: Dongju Chae <dongju.chae@samsung.com>
4 jobs for aarch64_support in 1 minute and 10 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Build
passed #802816
debian sid

00:00:52

passed #802819
docker windows 1607
msys2

00:01:01

passed #802817
docker windows 1607
vs2017 amd64

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passed #802818
docker windows 1607
vs2017 x86

00:01:06