Merge pull request #8039 from dotty-staging/fix-8015

Fix #8015: update docs

Author: nicolasstucki

docs/docs/internals/syntax.md

@@ -157,7 +157,7 @@ SimpleType        ::=  SimpleType TypeArgs
                     |  StableId
                     |  Path ‘.’ ‘type’                                          SingletonTypeTree(p)
                     |  ‘(’ ArgTypes ‘)’                                         Tuple(ts)
-                    |  ‘_’ SubtypeBounds
+                    |  ‘?’ SubtypeBounds
                     |  Refinement                                               RefinedTypeTree(EmptyTree, refinement)
                     |  SimpleLiteral                                            SingletonTypeTree(l)
                     |  ‘$’ ‘{’ Block ‘}’

docs/docs/reference/changed-features/vararg-patterns.md

@@ -36,5 +36,8 @@ The change to the grammar is:
 
 ## Compatibility considerations
 
-Under the `-language:Scala2Compat` option, Dotty will accept both the old and the new syntax.
-A migration warning will be emitted when the old syntax is encountered.
+To enable smooth cross compilation between Scala 2 and Scala 3, Dotty will
+accept both the old and the new syntax. Under the `-strict` setting, an error
+will be emitted when the old syntax is encountered. They will be enabled by
+default in version 3.1 of the language.
+