primitives: add count_nonzero

--HG--
extra : rebase_source : 3b1f9896842a2006b0d8e036f09c6dd2ef997ca4
cleanup unused variables

--HG--
extra : rebase_source : b71928a225427ef5031269223276e50fac4b5ff4
asm:  fix for illegal instruction usage in ipfilter

--HG--
extra : rebase_source : cbf94f214c79ff8e6a3aae1a94c99b3ada219575
testbench: adding seperate input buffer for idct and updated qp value for quant

--HG--
extra : rebase_source : 90a5abbf96528caa4a6d1d01f0bdd2f590c12d3c
asm: 16bpp code for quant and dequant_normal

--HG--
extra : rebase_source : 00d723aa76fdc9cb13556415e2ddd6c311964d58
asm : asm routine for chroma_p2s for 4:4:4 color space format

--HG--
extra : rebase_source : 782a237a4a4775be7d16eb8c157c7e2434e55413
testbench : test bench correction for chroma_p2s

--HG--
extra : rebase_source : cf60560554b1ffb58fc99d4823f93eefc7bc138d
TComRom: prevent multiple allocations or frees of globals
TComRom: use x265_malloc/free for globals
encoder: show per-slice type SSIM as dB
backout unintended commit