Fix breaks in the official build

[mellinoe]

There were two issues related to my recent change ( #18035 ):

• codeOptimization.targets was still trying to generate and restore a project.json file. This only happens when EnableProfileGuidedOptimization is set to true, which doesn't happen in CI builds. I've modified the targets file to use a checked-in MSBuild project instead. An unchanged version of codeOptimization.targets was checked in in order to show the diff (look at the second commit to see just the diff).
• optional.json was not being updated anymore, because I accidentally removed it from the list of projects being updated in dependencies.props. It was still being restored correctly, but the version numbers no longer matched up and the files from the packages were no longer being found. I've added it back into dependencies.props and manually sync'd back up the version numbers.
  • NOTE: optional.json is still a "project.json-based project". We don't use the CLI to restore this project; we use some built-in nuget task which supports encrypted credentials. This task still supports project.json restores.

@weshaggard

[ericstj]

FYI @dpodder who appears to be changing same targets in dotnet/buildtools#1427

[mellinoe]

@dpodder The changes look pretty simple to merge. I'll watch for a new version of buildtools and update corefx onto it and merge in the codeOptimization.targets changes into Tools-Override here.

[ericstj]

Do we actually need to copy it? The only reason I could imagine would be if nuget wasn't smart enough to invalidate the restore when we change the global properties. It's not like this was even doing incremental build all that well since the package name/version weren't in the path.

[mellinoe]

We don't strictly need to, but it does control where the intermediate outputs go to.

[ericstj]

... unless you pass in a property for that as well.

[mellinoe]

I'll do that in a follow-up. I'm going to merge now to unblock the official builds.

[ericstj]

Consider simplifying the restore target if it works correctly on the .msbuild file with only changing global properties.

[mellinoe]

I rebased on master so that CI won't hit the problem fixed by #18213.