Backported changes

• Revert #26579 and #25126 for binary compatibility #26813
• Preserve GADT constraints until PatternMatcher #26805
• Ignore @throws annotation on non-methods #26802
• Box bounded arguments of HKT result types in Java generic signatures #26787
• Fix issue with reading legal java cyclic signatures #26775
• Bail out of patDef opt for .runtimeChecked, not only @unchecked #26774
• Do not emit Java generic signatures for trait private val setters #26633
• Desugaring: avoid patdef optimization for lazy vals #26770
• Scaladoc: Fix variable expansion #26730

Contributors

Thank you to all the contributors who made this release possible 🎉

According to git shortlog -sn --no-merges 3.9.0-RC6..3.9.0-RC6 these are:

     7	Wojciech Mazur
     6	Patryk Zieliński
     4	Solal Pirelli
     2	Jan Chyb
     1	Rikito Taniguchi