rubocop: set LineLength to 118.

diagnostic: add doctor check for CPU arch on Linux

Co-Authored-By: Mike McQuaid <mike@mikemcquaid.com>

GitHub diff UI wraps beyond 118 characters. This also allows enabling
`Style/IfUnlessModifier` (which autocorrects).

diagnostic: check homebrew-core git status.

upgrade: suggest full_name when appropriate.

Also look in Homebrew/homebrew-core for uncommitted files (in some ways
we care about uncommitted stuff there more than Homebrew/brew). Also,
list all the modified files even when on non-CI to make it easier for
users to figure out their own issues and check the contents of the
whole repos rather than just a subdirectory.

In general this is a cleanup that should have been done long ago (when
we split Homebrew/brew and Homebrew/homebrew-core).

Otherwise `brew install foo/bar/baz` when an older version of `baz` is
installed will tell you to run `brew upgrade baz` which won't work.

build: bump unicode-display_width from 1.6.1 to 1.7.0 in /docs

Bumps [unicode-display_width](https://github.com/janlelis/unicode-display_width) from 1.6.1 to 1.7.0.
- [Release notes](https://github.com/janlelis/unicode-display_width/releases)
- [Changelog](https://github.com/janlelis/unicode-display_width/blob/master/CHANGELOG.md)
- [Commits](https://github.com/janlelis/unicode-display_width/compare/v1.6.1...v1.7.0

)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

formulary: fix typo.

"an commit" is not valid English.

formulary: strengthen commit URL warning.

formula_assertions: print output on assertion failed.

man: include full help from external commands.

build: bump octokit from 4.15.0 to 4.17.0 in /docs

Bumps [octokit](https://github.com/octokit/octokit.rb) from 4.15.0 to 4.17.0.
- [Release notes](https://github.com/octokit/octokit.rb/releases)
- [Changelog](https://github.com/octokit/octokit.rb/blob/4-stable/RELEASE.md)
- [Commits](https://github.com/octokit/octokit.rb/compare/v4.15.0...v4.17.0

)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Inspired by https://github.com/Homebrew/brew/issues/7148

Make clear these don't necessarily apply to all subcommands
(see https://github.com/Homebrew/brew/issues/7121).

cmd/uninstall: handle unparsed arguments.

Inspired by https://github.com/Homebrew/brew/issues/7154

Clarify tap issues should not be reported to Homebrew.

If `Homebrew.args` hasn't yet been populated then `named` will return
`nil`. Instead, ensure it is an array before we try to `join` it.

This is pretty much only a test-time problem but has been causing flaky
builds.

desc: fix search options

Instead, direct people to the actual tap.

rewrite_python_shebang: make version part optional

language/python: fix virtualenv symlinks for versioned Python

We forgot about the simplest case:
/usr/bin/env python

os/linux: implement sdk_path_if_needed

add https checking for links

When doing `brew test --verbose` (as `brew test-bot` does) ensure that
the output is printed when an assertion fails to more easily debug the
test failure.

formula: ensure CMake uses the desired SDK

patch: add support for changing directory