ShortcutImplicits conflicts with RefChecks

[allanrenucci]

class A

trait Foo {
  def foo: implicit A => Int
}

class Test {
  new FooI{}
}

class FooI extends Foo {
  def foo: implicit A => Int = 3
}

fails to compile:

> dotc Test.scala
-- Error: tests/allan/Test.scala:8:2 -------------------------------------------
8 |  new FooI{}
  |  ^
  |object creation impossible, since def foo$direct(implicit x$0: A): Int is not defined 

The issue is that at the time RefChecks transforms new FooI{}, class FooI hasn't gone through ShortcutImplicits which creates the member def foo$direct(implicit x$0: A): Int but trait Foo has

[allanrenucci]

Reopening as ShortcutImplicits still conflicts with RefChecks.

class Foo1 {
  def foo: implicit String => Int = 1
}

class Foo2 extends Foo1 {
  override def foo: implicit String => Int = 2
}

> dotc -d out tests/allan/Test.scala
-- Error: tests/allan/Test.scala:6:15 ------------------------------------------
6 |  override def foo: implicit String => Int = 2
  |               ^
  |error overriding method foo$direct in class Foo1 of type (implicit x$0: String): Int;
  |  method foo$direct of type (implicit x$0: String): Int needs `override' modifier
one error found