Add SSSE3 implementation for ipred_paeth

intra_pred_paeth_w4_8bpc_c: 561.6
intra_pred_paeth_w4_8bpc_ssse3: 49.2
intra_pred_paeth_w8_8bpc_c: 1475.8
intra_pred_paeth_w8_8bpc_ssse3: 103.0
intra_pred_paeth_w16_8bpc_c: 4697.8
intra_pred_paeth_w16_8bpc_ssse3: 279.0
intra_pred_paeth_w32_8bpc_c: 13245.1
intra_pred_paeth_w32_8bpc_ssse3: 614.7
intra_pred_paeth_w64_8bpc_c: 32638.9
intra_pred_paeth_w64_8bpc_ssse3: 1477.6
21 jobs for paeth in 6 minutes and 42 seconds (queued for 1 second)
Status Job ID Name Coverage
  Style
passed #269989
amd64 debian
style-check

00:00:25

 
  Build
passed #269990
amd64 debian
build-debian

00:00:39

passed #269998
debian aarch64
build-debian-aarch64

00:01:33

passed #269999
debian aarch64
build-debian-aarch64-clang-5

00:01:04

passed #270002
debian armv7
build-debian-armv7

00:02:40

passed #270003
debian armv7
build-debian-armv7-clang-5

00:01:14

passed #269991
amd64 debian
build-debian-static

00:00:39

passed #270001
debian aarch64
build-debian-werror

00:00:34

passed #269992
amd64 debian
build-debian32

00:00:36

passed #270000
macos
build-macos

00:00:26

passed #270004
amd64 debian
build-ubuntu-snap

00:00:45

passed #269996
amd64 debian
build-win-arm32

00:00:32

passed #269997
amd64 debian
build-win-arm64

00:00:35

passed #269993
amd64 debian
build-win32

00:00:46

passed #269994
amd64 debian
build-win32-unaligned-stack

00:00:41

passed #269995
amd64 debian
build-win64

00:00:51

 
  Test
passed #270005
amd64 debian
test-debian

00:00:50

passed #270006
amd64 debian
test-debian-asan

00:02:19

passed #270007
amd64 debian
test-debian-msan

00:01:12

passed #270008
amd64 debian
test-debian-ubsan

00:01:30

passed #270009
amd64 debian
test-win64

00:00:50