fdct8x8_test: add NEON functions
fdct8x8_test: add NEON functions

FwdTrans8x8HT is disabled as the tests currently fail.

note not all functions have NEON implementations:
- fdct8x8/fht8x8

Change-Id: I028bdec9a21eaaee2c5865470ab179aac403540e

Laknot/libvpx,liqianggao/libvpx,hsueceumd/test_hui,Distrotech/libvpx,pcwalton/libvpx,smarter/aom,matanbs/vp982,ittiamvpx/libvpx-1,ittiamvpx/libvpx,Suvarna1488/webm.libvpx,hsueceumd/test_hui,GrokImageCompression/aom,matanbs/vp982,gshORTON/webm.libvpx,reimaginemedia/webm.libvpx,jacklicn/webm.libvpx,Maria1099/webm.libvpx,felipebetancur/libvpx,abwiz0086/webm.libvpx,matanbs/vp982,abwiz0086/webm.libvpx,shyamalschandra/libvpx,lyx2014/libvpx_c,WebRTC-Labs/libvpx,stewnorriss/libvpx,felipebetancur/libvpx,Topopiccione/libvpx,mwgoldsmith/vpx,openpeer/libvpx_new,jdm/libvpx,iniwf/webm.libvpx,zofuthan/libvpx,abwiz0086/webm.libvpx,ittiamvpx/libvpx,gshORTON/webm.libvpx,smarter/aom,gshORTON/webm.libvpx,ittiamvpx/libvpx,abwiz0086/webm.libvpx,jacklicn/webm.libvpx,mwgoldsmith/libvpx,lyx2014/libvpx_c,openpeer/libvpx_new,WebRTC-Labs/libvpx,altogother/webm.libvpx,Acidburn0zzz/webm.libvpx,jdm/libvpx,Suvarna1488/webm.libvpx,mbebenita/aom,Suvarna1488/webm.libvpx,Laknot/libvpx,shareefalis/libvpx,zofuthan/libvpx,shyamalschandra/libvpx,liqianggao/libvpx,mwgoldsmith/libvpx,mbebenita/aom,GrokImageCompression/aom,goodleixiao/vpx,gshORTON/webm.libvpx,ittiamvpx/libvpx-1,shacklettbp/aom,ittiamvpx/libvpx-1,luctrudeau/aom,shyamalschandra/libvpx,jdm/libvpx,running770/libvpx,jmvalin/aom,matanbs/webm.libvpx,lyx2014/libvpx_c,Distrotech/libvpx,lyx2014/libvpx_c,jacklicn/webm.libvpx,iniwf/webm.libvpx,Laknot/libvpx,hsueceumd/test_hui,iniwf/webm.libvpx,GrokImageCompression/aom,n4t/libvpx,jdm/libvpx,hsueceumd/test_hui,thdav/aom,reimaginemedia/webm.libvpx,matanbs/vp982,altogother/webm.libvpx,Topopiccione/libvpx,mbebenita/aom,luctrudeau/aom,kalli123/webm.libvpx,running770/libvpx,lyx2014/libvpx_c,felipebetancur/libvpx,kalli123/webm.libvpx,luctrudeau/aom,kim42083/webm.libvpx,pcwalton/libvpx,Distrotech/libvpx,n4t/libvpx,mbebenita/aom,thdav/aom,n4t/libvpx,kalli123/webm.libvpx,liqianggao/libvpx,hsueceumd/test_hui,webmproject/libvpx,WebRTC-Labs/libvpx,goodleixiao/vpx,Acidburn0zzz/webm.libvpx,kim42083/webm.libvpx,thdav/aom,altogother/webm.libvpx,Acidburn0zzz/webm.libvpx,kim42083/webm.libvpx,ittiamvpx/libvpx,matanbs/vp982,mwgoldsmith/libvpx,shareefalis/libvpx,ittiamvpx/libvpx-1,stewnorriss/libvpx,mbebenita/aom,Maria1099/webm.libvpx,Maria1099/webm.libvpx,matanbs/webm.libvpx,hsueceumd/test_hui,n4t/libvpx,kalli123/webm.libvpx,jacklicn/webm.libvpx,Acidburn0zzz/webm.libvpx,Maria1099/webm.libvpx,shacklettbp/aom,kim42083/webm.libvpx,reimaginemedia/webm.libvpx,shareefalis/libvpx,matanbs/webm.libvpx,Acidburn0zzz/webm.libvpx,jdm/libvpx,abwiz0086/webm.libvpx,zofuthan/libvpx,goodleixiao/vpx,ittiamvpx/libvpx-1,goodleixiao/vpx,altogother/webm.libvpx,Laknot/libvpx,mwgoldsmith/vpx,jmvalin/aom,ittiamvpx/libvpx,ShiftMediaProject/libvpx,zofuthan/libvpx,webmproject/libvpx,kleopatra999/webm.libvpx,zofuthan/libvpx,openpeer/libvpx_new,kim42083/webm.libvpx,WebRTC-Labs/libvpx,jacklicn/webm.libvpx,thdav/aom,charup/https---github.com-webmproject-libvpx-,shyamalschandra/libvpx,shareefalis/libvpx,GrokImageCompression/aom,kalli123/webm.libvpx,Distrotech/libvpx,luctrudeau/aom,ShiftMediaProject/libvpx,mbebenita/aom,Topopiccione/libvpx,jmvalin/aom,VTCSecureLLC/libvpx,kleopatra999/webm.libvpx,running770/libvpx,running770/libvpx,charup/https---github.com-webmproject-libvpx-,openpeer/libvpx_new,gshORTON/webm.libvpx,openpeer/libvpx_new,GrokImageCompression/aom,pcwalton/libvpx,kim42083/webm.libvpx,iniwf/webm.libvpx,Maria1099/webm.libvpx,running770/libvpx,Distrotech/libvpx,mbebenita/aom,charup/https---github.com-webmproject-libvpx-,felipebetancur/libvpx,Laknot/libvpx,openpeer/libvpx_new,reimaginemedia/webm.libvpx,ittiamvpx/libvpx-1,thdav/aom,webmproject/libvpx,altogother/webm.libvpx,Suvarna1488/webm.libvpx,pcwalton/libvpx,n4t/libvpx,stewnorriss/libvpx,charup/https---github.com-webmproject-libvpx-,matanbs/vp982,abwiz0086/webm.libvpx,Suvarna1488/webm.libvpx,kleopatra999/webm.libvpx,jmvalin/aom,mwgoldsmith/vpx,iniwf/webm.libvpx,reimaginemedia/webm.libvpx,luctrudeau/aom,charup/https---github.com-webmproject-libvpx-,webmproject/libvpx,shacklettbp/aom,shacklettbp/aom,stewnorriss/libvpx,Topopiccione/libvpx,mbebenita/aom,Distrotech/libvpx,ittiamvpx/libvpx,goodleixiao/vpx,mwgoldsmith/libvpx,shacklettbp/aom,mbebenita/aom,stewnorriss/libvpx,jdm/libvpx,Topopiccione/libvpx,Laknot/libvpx,matanbs/webm.libvpx,goodleixiao/vpx,webmproject/libvpx,VTCSecureLLC/libvpx,shacklettbp/aom,Topopiccione/libvpx,pcwalton/libvpx,VTCSecureLLC/libvpx,stewnorriss/libvpx,shyamalschandra/libvpx,iniwf/webm.libvpx,mwgoldsmith/vpx,kalli123/webm.libvpx,pcwalton/libvpx,shyamalschandra/libvpx,lyx2014/libvpx_c,felipebetancur/libvpx,liqianggao/libvpx,liqianggao/libvpx,smarter/aom,smarter/aom,kleopatra999/webm.libvpx,jmvalin/aom,mwgoldsmith/vpx,VTCSecureLLC/libvpx,charup/https---github.com-webmproject-libvpx-,matanbs/webm.libvpx,smarter/aom,jmvalin/aom,luctrudeau/aom,WebRTC-Labs/libvpx,zofuthan/libvpx,ShiftMediaProject/libvpx,mwgoldsmith/libvpx,jacklicn/webm.libvpx,kleopatra999/webm.libvpx,webmproject/libvpx,altogother/webm.libvpx,felipebetancur/libvpx,thdav/aom,smarter/aom,gshORTON/webm.libvpx,Maria1099/webm.libvpx,kleopatra999/webm.libvpx,matanbs/webm.libvpx,liqianggao/libvpx,mwgoldsmith/vpx,shareefalis/libvpx,mwgoldsmith/libvpx,ShiftMediaProject/libvpx,Suvarna1488/webm.libvpx,shareefalis/libvpx,VTCSecureLLC/libvpx,Acidburn0zzz/webm.libvpx,reimaginemedia/webm.libvpx,running770/libvpx,matanbs/vp982,ShiftMediaProject/libvpx,GrokImageCompression/aom,VTCSecureLLC/libvpx