Integrate github.com/docker/docker/pkg/system Sequential utilities

[thaJeztah]

Integrate github.com/docker/docker/pkg/system Sequential utilities

Integrating the "Sequential" utilities from github.com/docker/docker/pkg/system,
taken from commit 3e8573a85a42d4882068bffab7d83f5d93d417e1

Steps taken:

# install filter-repo (https://github.com/newren/git-filter-repo/blob/main/INSTALL.md)
brew install git-filter-repo

# create a temporary clone of docker
cd ~/Projects
git clone https://github.com/docker/docker.git moby_sys
cd moby_sys

# commit taken from
git rev-parse --verify HEAD
3e8573a85a42d4882068bffab7d83f5d93d417e1

# remove all code, except for 'pkg/system/filesys_*.go', and rename to /sequential
git filter-repo \
  --path-glob 'pkg/system/filesys_*.go' \
  --path-rename pkg/system/filesys_unix.go:sequential/sequential_unix.go \
  --path-rename pkg/system/filesys_windows.go:sequential/sequential_windows.go

# go to the target github.com/moby/sys repository
cd ~/go/src/github.com/moby/sys

# create a branch to work with
git checkout -b integrate_moby_sequential

# add the temporary repository as an upstream and make sure it's up-to-date
git remote add moby_sys ~/Projects/moby_sys
git fetch moby_sys

# merge the upstream code
git merge --allow-unrelated-histories --signoff -S moby_sys/master

sequential: initialize module, and remove unrelated functions

sequential: rename funcs to match their "os" equivalent

Rename the functions so that they can act as a drop-in replacement
for their "os" equivalents.

[thaJeztah]

@kolyshkin @kzys @AkihiroSuda @dims PTAL

[dims]

thanks @thaJeztah for saving the commit info from the other repo!

[AkihiroSuda]

Not new in this PR, but probably we have to replicate the original copyright header

[thaJeztah]

Ah, good point; perhaps extract the bits that were copied to a separate file (I'd have to check how much was copied; I think that's only in the CreateTemp, which uses similar /same logic as os.CreateTemp)

We can look at that in a follow up in deed 👍

[thaJeztah]

FWIW; was also discussing with @crazy-max to see to what extend we still need that function; it may be that some parts were needed for "pre go1.9" code, which didn't work well with Windows, but some of those reasons may no longer be there, so possibly we can start to remove some of this.

I think it's still useful to first do the migration, and go from there though (proposing to tag it as v0.5, so that any deprecation that would happen could be done before v1.0.0).

[thaJeztah]

I'll bring this one in, and update the PR's in other projects that were opened to move to this module.

If those "look good", I'll tag a v0.5.0 release