It would probably help a lot if there were a dedicated list for changes to the AST in v0.7, since some packages are implicitly intertwined with the AST, making it difficult to find all the potential issues immediately.
While some are mentioned in NEWs, the most complete reference doc should be: https://github.com/JuliaLang/julia/commits/master/doc/src/devdocs/ast.md “Surface syntax AST”
Please open PRs to add new content (or at least headers for new content) if you see that it’s missing a section.