Clean up non-core commands

[neonichu]

This separates out the collections and registry commands from the Commands module, allowing to simplify the first stage of bootstrap:

• Moves the command implementations to new modules PackageCollectionsTool and PackageRegistryTool.
• Adds a new multi-tool entry point executable swift-package-manager. This used to be included in swift-package, but that would render the separation moot and also seems like a better structure. For installation into the toolchain, we're simply installing the new executable under the name swift-package, so nothing changes there.
• Remove package-collections related stuff from the CMake build, it was anyway completely unused.

[neonichu]

@swift-ci please smoke test

[neonichu]

@swift-ci please smoke test

[neonichu]

@swift-ci please smoke test

[MaxDesiatov]

• Moves the command implementations to new modules PackageCollectionsTool and PackageRegistryTool.

Based on this, would you like experimental-destinations command introduced in #5911 to be moved to a separate module too?

[neonichu]

Based on this, would you like experimental-destinations command introduced in #5911 to be moved to a separate module too?

I think it's fine to be in Commands since it doesn't need further dependencies. The main goal of this is to thin out the number of things that need to be built with CMake and to ideally not grow them.

[neonichu]

--- bootstrap: note: Installing /home/build-user/build/buildbot_incremental/swiftpm-linux-x86_64/x86_64-unknown-linux-gnu/release/swift-package-manager to /home/build-user/build/buildbot_incremental/toolchain-linux-x86_64/usr/bin/swift-package/swift-package-manager

Looks like the change to bootstrap is not quite right, it is creating a directory called swift-package 😆

[neonichu]

@swift-ci please smoke test

[tomerd]

🥳

[tomerd]

cc @yim-lee

[neonichu]

@swift-ci please test package compatibility

[neonichu]

Hmmmm

[/Users/ec2-user/jenkins/workspace-private/swift-package-manager-source-compat-suite-PR-macos/swift/utils/build-script] ERROR: can't find CMake (please install CMake)

Is that an infra issue, @shahmishal?

[neonichu]

@swift-ci please test package compatibility

[MaxDesiatov]

• Adds a new multi-tool entry point executable swift-package-manager.

Is this new multi-tool entry point supposed to be the only one available? Is there much sense in declaring separate executableTargets for new top-level commands, in addition to adding a case to this entry point?

[neonichu]

Is this new multi-tool entry point supposed to be the only one available? Is there much sense in declaring separate executableTargets for new top-level commands, in addition to adding a case to this entry point?

Yes, for two reasons:

• not all platforms support symlinks in the way Unix-style platforms do, so e.g. on Windows we will not use the multi-tool but instead the individual binaries
• for local testing/debugging, it can be useful to just build and run the individual tools, especially because the symlinking is not something that we can currently express in SwiftPM, so only builds with the bootstrap scripts have them.