Make case classes Serializable

[OlivierBlanvillain]

No description provided.

[OlivierBlanvillain]

@nicolasstucki How do I regenerate these files:?

• run/literals.decompiled
• pos/i2104b.decompiled
• pos/simpleCaseObject.decompiled
• pos/simpleCaseClass-3.decompiled
• pos/simpleCaseClass-2.decompiled
• pos/simpleCaseClass-1.decompiled

[nicolasstucki]

Run testFromTasty i2104b, it will generate pos/i2104b.decompiled.out.

[smarter]

We should really automatize this: in scalac, partest --update-check will automatically update all failing check files.

[OlivierBlanvillain]

$ sbt "testFromTasty i2104b" && mv pos/i2104b.decompiled{.out,}
...
mv: cannot stat 'pos/i2104b.decompiled.out': No such file or directory

[smarter]

tests/pos instead of pos ?

[smarter]

For some reason this PR broke the typeclass derivation tests, fixed by adding with Serializable in a few places but that doesn't seem optimal: 7705113 /cc @odersky

[liufengyun]

Should we avoid adding Serializable if the case class already extends Serializable?

[smarter]

@liufengyun Yes, just like scalac we should allow explicitly extending Serializable or Product in a case class without error, can you create an issue for that ?