WIP: arm: Add helpers for debug printing from assembly

These currently print GPRs, and print SIMD registers as s16, and
prints generic memory addresses as s16 vectors.
38 jobs for arm-asm-dump in 7 minutes and 13 seconds (queued for 4 seconds)
Status Job ID Name Coverage
  Style
passed style-check #664940
amd64 docker

00:00:07

passed x86inc-check #664941
amd64 docker

00:00:07

 
  Build
passed build-android-aarch64 #664956
amd64 docker

00:00:09

passed build-android-armv7 #664955
amd64 docker

00:00:12

passed build-debian #664942
amd64 avx2 docker

00:00:36

passed build-debian-aarch64 #664957
aarch64 docker

00:00:17

passed build-debian-aarch64-clang-5 #664958
aarch64 docker

00:00:14

passed build-debian-armv7 #664961
armv7 docker

00:02:09

passed build-debian-armv7-clang-5 #664962
armv7 docker

00:01:19

passed build-debian-bitdepth-16 #664949
amd64 docker

00:00:13

passed build-debian-bitdepth-8 #664948
amd64 docker

00:00:20

passed build-debian-examples #664946
amd64 docker

00:00:16

passed build-debian-illegal-instructions #664944
amd64 avx2 docker

00:01:39

passed build-debian-no-tools #664947
amd64 docker

00:00:17

passed build-debian-ppc64le #664964
ppc64le docker

00:01:09

passed build-debian-static #664943
amd64 docker

00:00:33

passed build-debian-werror #664960
aarch64 docker

00:00:10

passed build-debian32 #664945
amd64 docker

00:00:21

passed build-macos #664959
catalina amd64

00:00:50

passed build-pages #664965
amd64 docker

00:00:10

passed build-ubuntu-snap #664963
amd64 docker

00:00:20

passed build-win-arm32 #664953
amd64 docker

00:00:10

passed build-win-arm64 #664954
amd64 docker

00:00:14

passed build-win32 #664950
amd64 docker

00:00:29

passed build-win32-unaligned-stack #664951
amd64 docker

00:00:28

passed build-win64 #664952
amd64 docker

00:00:47

 
  Test
passed test-debian #664966
amd64 docker

00:01:13

95.3821%
passed test-debian-aarch64 #664975
aarch64 docker

00:01:40

passed test-debian-armv7-clang-5 #664977
armv7 docker

00:03:35

passed test-debian-asan #664970
amd64 docker

00:02:01

passed test-debian-asm #664967
avx2 amd64 docker

00:01:06

passed test-debian-msan #664971
amd64 docker

00:00:58

passed test-debian-ppc64le #664976
ppc64le docker

00:02:32

passed test-debian-tsan #664973
amd64 docker

00:02:47

passed test-debian-ubsan #664972
amd64 docker

00:01:20

passed test-debian-unaligned-stack #664969
amd64 avx2 docker

00:01:00

passed test-debian32-asm #664968
avx2 amd64 docker

00:01:08

passed test-win64 #664974
amd64 avx2 docker

00:04:49