ARM32/64 NEON versions of ScaleRowDown2Linear_NEON are implemented.

BUG=319
TESTED=libyuvTest.ScaleDownBy2_Linear on ARM32/64 with Android
R=fbarchard@google.com

Change-Id: I2c7f43a0d56ed4dfded5bdbbb61765d87d65a2ba

Review URL: https://webrtc-codereview.appspot.com/43519005

git-svn-id: http://libyuv.googlecode.com/svn/trunk@1307 16f28f9a-4ce2-e073-06de-1de4eb20be90

BUG=357
TESTED=ios arm64 build
R=tpsiaki@google.com

Review URL: https://webrtc-codereview.appspot.com/29429004

git-svn-id: http://libyuv.googlecode.com/svn/trunk@1083 16f28f9a-4ce2-e073-06de-1de4eb20be90

BUG=333
TESTED=ncval
R=thorcarpenter@google.com

Review URL: https://webrtc-codereview.appspot.com/20719004

git-svn-id: http://libyuv.googlecode.com/svn/trunk@1017 16f28f9a-4ce2-e073-06de-1de4eb20be90

port neon to arm64. the register names have changes from r0 to w0 or x0 depending on size.  Passing them as parameters (e.g. %0) makes the code register name agnostic.
BUG=333
TESTED=32 bit build still works.
R=nfullagar@chromium.org

Review URL: https://webrtc-codereview.appspot.com/20669005

git-svn-id: http://libyuv.googlecode.com/svn/trunk@1016 16f28f9a-4ce2-e073-06de-1de4eb20be90

BUG=333
TESTED=ncval
R=tpsiaki@google.com

Review URL: https://webrtc-codereview.appspot.com/18549004

git-svn-id: http://libyuv.googlecode.com/svn/trunk@1015 16f28f9a-4ce2-e073-06de-1de4eb20be90

BUG=333
TESTED=d:\src\nacl_sdk\pepper_canary\tools\ncval.exe newlib/Release/nacltest_arm.nexe
R=nfullagar@chromium.org

Review URL: https://webrtc-codereview.appspot.com/17599004

git-svn-id: http://libyuv.googlecode.com/svn/trunk@1006 16f28f9a-4ce2-e073-06de-1de4eb20be90

BUG=303
TEST=compile -x c

Review URL: https://webrtc-codereview.appspot.com/6599006

git-svn-id: http://libyuv.googlecode.com/svn/trunk@954 16f28f9a-4ce2-e073-06de-1de4eb20be90

Neon RGBToUV more accurate coefficients and subsample averaging.  Instead of adding 4 pixels and making coefficients 4x smaller, this makes the coefficients 2x small and does a shift, for best accuracy.
BUG=297
TESTED=try bots
R=tpsiaki@google.com, yunqingwang@google.com

Review URL: https://webrtc-codereview.appspot.com/6309004

git-svn-id: http://libyuv.googlecode.com/svn/trunk@920 16f28f9a-4ce2-e073-06de-1de4eb20be90

Reduce alignment for loops from 16 bytes to 4 bytes.  Reduces outer loop overhead without hurting innerloop time.
BUG=none
TESTED=try bots
R=fbarchard@chromium.org, mflodman@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/4659004

git-svn-id: http://libyuv.googlecode.com/svn/trunk@880 16f28f9a-4ce2-e073-06de-1de4eb20be90

BUG=none
TEST=untested
R=tpsiaki@google.com

Review URL: https://webrtc-codereview.appspot.com/4509005

git-svn-id: http://libyuv.googlecode.com/svn/trunk@879 16f28f9a-4ce2-e073-06de-1de4eb20be90

BUG=258
TEST=try bots
R=johannkoenig@google.com

Review URL: https://webrtc-codereview.appspot.com/1944004

git-svn-id: http://libyuv.googlecode.com/svn/trunk@743 16f28f9a-4ce2-e073-06de-1de4eb20be90

Change vld and vst to specify only elements and size not sign for better arm compiler compatability.
BUG=none
TEST=none
R=kma@webrtc.org, mflodman@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/1643004

git-svn-id: http://libyuv.googlecode.com/svn/trunk@721 16f28f9a-4ce2-e073-06de-1de4eb20be90

BUG=232
TEST=convert.exe -f 0 faces_640x480_P420.yuv face2_160x120_P420.yuv
R=changjun.yang@intel.com

Review URL: https://webrtc-codereview.appspot.com/1579005

git-svn-id: http://libyuv.googlecode.com/svn/trunk@709 16f28f9a-4ce2-e073-06de-1de4eb20be90

Specialized scale down sample to 1 / 2 size adjust to match general purpose code which uses odd pixel (rounded up - nearest neighbor).
BUG=223
TEST=out\Debug\convert.exe -f 0 faces_640x480_P420.yuv face2_320x240_P420.yuv
R=johannkoenig@google.com

Review URL: https://webrtc-codereview.appspot.com/1583005

git-svn-id: http://libyuv.googlecode.com/svn/trunk@708 16f28f9a-4ce2-e073-06de-1de4eb20be90

BUG=189
TESTED=try
Review URL: https://webrtc-codereview.appspot.com/1113006

git-svn-id: http://libyuv.googlecode.com/svn/trunk@582 16f28f9a-4ce2-e073-06de-1de4eb20be90

BUG=none
TEST=lint
Review URL: https://webrtc-codereview.appspot.com/1063010

git-svn-id: http://libyuv.googlecode.com/svn/trunk@553 16f28f9a-4ce2-e073-06de-1de4eb20be90

BUG=none
TEST=lint
Review URL: https://webrtc-codereview.appspot.com/931013

git-svn-id: http://libyuv.googlecode.com/svn/trunk@496 16f28f9a-4ce2-e073-06de-1de4eb20be90

BUG=none
TEST=./libyuv_unittest --gtest_filter=*ARGBScale*
Review URL: https://webrtc-codereview.appspot.com/964016

git-svn-id: http://libyuv.googlecode.com/svn/trunk@494 16f28f9a-4ce2-e073-06de-1de4eb20be90

BUG=none
TEST=none
Review URL: https://webrtc-codereview.appspot.com/938014

git-svn-id: http://libyuv.googlecode.com/svn/trunk@486 16f28f9a-4ce2-e073-06de-1de4eb20be90

BUG=none
TEST=none
Review URL: https://webrtc-codereview.appspot.com/922007

git-svn-id: http://libyuv.googlecode.com/svn/trunk@437 16f28f9a-4ce2-e073-06de-1de4eb20be90

BUG=none
TEST=none
Review URL: https://webrtc-codereview.appspot.com/860009

git-svn-id: http://libyuv.googlecode.com/svn/trunk@396 16f28f9a-4ce2-e073-06de-1de4eb20be90