Definitions in java.lang._ shadow definitions in REPL

[nicolasstucki]

The current error messages are also not helpful to understand that those definitions are shadowed.

scala> class Compiler
scala> new Compiler
  |        ^^^^^^^^
  |constructor Compiler cannot be accessed as a member of Compiler from module class rs$line$7$.

scala> class Appendable
scala> new Appendable
1 |new Appendable
  |    ^^^^^^^^^^
  |    Appendable is a trait; it cannot be instantiated

scala> class Byte
scala> new Byte
1 |new Byte
  |    ^^^^
  |    Byte is abstract; it cannot be instantiated

scala> class Compiler
scala> new Compiler
  |        ^^^^^^^^
  |constructor Compiler cannot be accessed as a member of Compiler from module class rs$line$7$.

[nicolasstucki]

Also see comment https://github.com/lampepfl/dotty/pull/11129/files#r559526476

[som-snytt]

REPL definitions should shadow classpath and root contexts.

#7635 (comment)