Third one is perf oriented:
* proc-macro2 v1.0.30 -> v1.0.37 https://github.com/dtolnay/proc-macro2/compare/1.0.30...1.0.37 (https://github.com/dtolnay/proc-macro2/releases, for example https://github.com/dtolnay/proc-macro2/releases/tag/1.0.36)
* quote v1.0.7 -> v1.0.18 https://github.com/dtolnay/quote/compare/1.0.7...1.0.18 (https://github.com/dtolnay/quote/releases) multiple perf improvements: https://github.com/dtolnay/quote/releases/tag/1.0.16, https://github.com/dtolnay/quote/releases/tag/1.0.14, https://github.com/dtolnay/quote/releases/tag/1.0.11
* syn v1.0.80 -> v1.0.91 https://github.com/dtolnay/syn/compare/1.0.80...1.0.91 (https://github.com/dtolnay/syn/releases): didn't find good examples, but given, that there exist private api across `proc-macro2`, `quote` by the same author, *i think* it may take advantage of it.