Also consider private symbols in implicit scope of type

Fixes #14013

Author: odersky

compiler/src/dotty/tools/dotc/typer/Implicits.scala

@@ -287,7 +287,7 @@ object Implicits:
       }
 
     override def isAccessible(ref: TermRef)(using Context): Boolean =
-      ref.symbol.exists && !ref.symbol.is(Private)
+      ref.symbol.exists
 
     override def toString: String =
       i"OfTypeImplicits($tp), companions = ${companionRefs.showAsList}%, %; refs = $refs%, %."

tests/neg/i14013.scala

@@ -0,0 +1,15 @@
+object Foo1 {
+  case class Bar(i: Int)
+
+  private implicit class BarOps(bar: Bar) {
+    def twice = Bar(bar.i * 2)
+  }
+}
+
+class Foo {
+  def bar = Foo.Bar(1).twice // error
+}
+
+object App extends App {
+  println((new Foo).bar)
+}

tests/pos/i14013.scala

@@ -0,0 +1,15 @@
+object Foo {
+  case class Bar(i: Int)
+
+  private implicit class BarOps(bar: Bar) {
+    def twice = Bar(bar.i * 2)
+  }
+}
+
+class Foo {
+  def bar = Foo.Bar(1).twice
+}
+
+object App extends App {
+  println((new Foo).bar)
+}