Batch up libsyntax breaking changes

[jseyfried]

Batch of the following syntax-[breaking-change] changes:

• Add support for macro expansion inside trait items #34213: Add a variant Macro to TraitItemKind
• Merge PatKind::QPath into PatKind::Path in AST #34368: Merge the variant QPath of PatKind into the variant PatKind::Path
• Factor TokenTrees into their own file in preparation for TokenStreams. #34385: Move syntax::ast::TokenTree into a new module syntax::tokenstream
• libsyntax: miscellaneous cleanup #33943:
  • Remove the type parameter from visit::Visitor
  • Remove attr::WithAttrs -- use attr::HasAttrs instead.
  • Change fold_tt/fold_tts to take token trees by value and avoid wrapping token trees in Rc.
  • Remove the field ctxt of ast::Mac_
  • Remove inherent method attrs() of types -- use the method attrs of HasAttrs instead.
• Refactor ast::Stmt and rename ExprKind::Again to Continue #34316:
  • Remove ast::Decl/ast::DeclKind and add variants Local and Item to StmtKind.
  • Move the node id for statements from the StmtKind variants to a field of Stmt (making Stmt a struct instead of an alias for Spanned<StmtKind>)
  • Rename ast::ExprKind::Again to Continue.
• Generalize and abstract ThinAttributes to ThinVec<Attribute> #34339: Generalize and abstract ThinAttributes to ThinVec<Attribute>
  • Use .into() in convert between Vec<Attribute> and ThinVec<Attribute>
  • Use autoderef instead of .as_attr_slice()
• Allow statement-generating braced macro invocations at the end of blocks #34436: Remove the optional expression from ast::Block and instead use a StmtKind::Expr at the end of the statement list.
• Move errors from libsyntax into their own crate #34403: Move errors into a separate crate (unlikely to cause breakage)

[Manishearth]

I prefer having reviewer info stick around in the merge commit somehow. I have a process for this 😄

[Manishearth]

you may also find this git alias useful for future stuff: fetchpr = !sh -c 'git fetch $1 pull/$2/head:pr-$2' -

[jseyfried]

Ok, didn't mean to disrupt your process. There were a lot of merge conflicts, mostly from my PRs, so I figured I'd take care of them. If you'd like to integrate that work from this branch into your process, feel free :)

[Manishearth]

Nah, it's fine. I'm okay with others doing it, just leave the reviewer info and PR text in there somehow. Especially if you've already fixed merge conflicts.

Could you use git rebase master --preserve-merges and just edit the commit text of the merge commits? I have code that does this already (not for rebases though), basically a mergerollup command in bash:

mergerollup() {
 echo "Merging $@"
 git branch -D current
 git fetch origin pull/$2/head:current
 NL="

"
 A=$(wget -O - https://api.github.com/repos/rust-lang/rust/pulls/$2 -q| grep "\"body\":"| sed  's/^  "body": "//'|sed 's/",$//'| sed 's/\\n/\n/g' | sed 's/\\r//g')

 git merge --no-ff current -m "Rollup merge of #$2 - $1, r=$3 $NL $A";
 git mergetool
}

which can be run using the code in #31645 (comment)

[jseyfried]

Will do.

[bors]

☔ The latest upstream changes (presumably #34253) made this pull request unmergeable. Please resolve the merge conflicts.

[bors]

📌 Commit 542ba8c has been approved by Manishearth

[sophiajt]

@jseyfried - thanks :)

[bors]

⌛ Testing commit 542ba8c with merge df7ef54...

[bors]

💔 Test failed - auto-linux-64-opt-rustbuild

[jseyfried]

@bors force r=Manishearth

[bors]

📌 Commit 360dcae has been approved by Manishearth

[bors]

⌛ Testing commit 360dcae with merge ea0dc92...

[bors]

☀️ Test successful - auto-linux-32-nopt-t, auto-linux-32-opt, auto-linux-64-cargotest, auto-linux-64-cross-freebsd, auto-linux-64-debug-opt, auto-linux-64-nopt-t, auto-linux-64-opt, auto-linux-64-opt-mir, auto-linux-64-opt-rustbuild, auto-linux-64-x-android-t, auto-linux-cross-opt, auto-linux-musl-64-opt, auto-mac-32-opt, auto-mac-64-opt, auto-mac-64-opt-rustbuild, auto-mac-cross-ios-opt, auto-win-gnu-32-opt, auto-win-gnu-32-opt-rustbuild, auto-win-gnu-64-opt, auto-win-msvc-32-opt, auto-win-msvc-64-cargotest, auto-win-msvc-64-opt, auto-win-msvc-64-opt-mir, auto-win-msvc-64-opt-rustbuild

[dtolnay]

That top comment is really helpful, thanks @jseyfried.