Specialize erasure of `synchronized` primitive method

The goal is to avoid emitting unneeded `BoxedUnit` values,
which are the result of adapting a `Unit`-typed expression
inside a `synchronized(...)` to the erased type of
`synchronized`'s argument -- `Object`.

The proposed solution gives `synchronized` a polymorphic
type (the info of the type param is still erased so that
bounds checking works in the erased type system), so that
an application `synchronized(println("boo"))` erases to
`synchronized[Unit])(println("boo"))`, and no boxing is
performed on the `println("boo")` argument, whose expected
type is now `Unit` instead of `Object`.

0 files changed, 0 insertions, 0 deletions