Introduce deprecation of companion objects nested classes

Introdude deprecation as per KT-21515. Warning is reported on type
usage, that soon will became invisible. Quickfix by adding explicit
import is added.

Idea behind implementation is to mark scopes that are deprecated (see
ClassResolutionScopesSupport).

Then, during walk along hierarchy of scopes, look at deprecation status
of the scope that has provided this classifier.
Note that we also have to check if there are *some* non-deprecated
visibility paths (because we can see classifier by two paths, e.g. if
we've added explicit import) -- then this type reference shouldn't be
treated as deprecated.

idea/testData/editor/optimizeImports/common/kt21515/callableReferenceOnClass.kt

@@ -0,0 +1,29 @@
+package foo
+
+import foo.CallableReferenceOnClass.Base.Companion.FromBaseCompanion
+import foo.CallableReferenceOnClass.CompanionSupertype.FromCompanionSupertype
+
+object CallableReferenceOnClass {
+
+    open class Base {
+        companion object {
+            class FromBaseCompanion {
+                fun foo() = 42
+            }
+        }
+    }
+
+    open class CompanionSupertype {
+        class FromCompanionSupertype {
+            fun foo() = 42
+        }
+    }
+}
+
+class Derived : CallableReferenceOnClass.Base() {
+    companion object : CallableReferenceOnClass.CompanionSupertype() { }
+
+    // Callable references
+    val c = FromBaseCompanion::foo
+    val d = FromCompanionSupertype::foo
+}

idea/testData/editor/optimizeImports/common/kt21515/callableReferenceOnClass.kt.after

@@ -0,0 +1,29 @@
+package foo
+
+import foo.CallableReferenceOnClass.Base.Companion.FromBaseCompanion
+import foo.CallableReferenceOnClass.CompanionSupertype.FromCompanionSupertype
+
+object CallableReferenceOnClass {
+
+    open class Base {
+        companion object {
+            class FromBaseCompanion {
+                fun foo() = 42
+            }
+        }
+    }
+
+    open class CompanionSupertype {
+        class FromCompanionSupertype {
+            fun foo() = 42
+        }
+    }
+}
+
+class Derived : CallableReferenceOnClass.Base() {
+    companion object : CallableReferenceOnClass.CompanionSupertype() { }
+
+    // Callable references
+    val c = FromBaseCompanion::foo
+    val d = FromCompanionSupertype::foo
+}

idea/testData/editor/optimizeImports/common/kt21515/callableReferenceOnClassWithCompanion.kt

@@ -0,0 +1,35 @@
+package foo
+
+import foo.CallableReferenceOnClassWithCompanion.Base.Companion.FromBaseCompanion
+import foo.CallableReferenceOnClassWithCompanion.CompanionSupertype.FromCompanionSupertype
+
+object CallableReferenceOnClassWithCompanion {
+
+    open class Base {
+        companion object {
+            class FromBaseCompanion {
+                fun foo() = 42
+
+                // We need it to cover another code-path
+                companion object
+            }
+        }
+    }
+
+    open class CompanionSupertype {
+        class FromCompanionSupertype {
+            fun foo() = 42
+
+            // We need it to cover another code-path
+            companion object
+        }
+    }
+}
+
+class Derived : CallableReferenceOnClassWithCompanion.Base() {
+    companion object : CallableReferenceOnClassWithCompanion.CompanionSupertype() { }
+
+    // Callable references
+    val c = FromBaseCompanion::foo
+    val d = FromCompanionSupertype::foo
+}

idea/testData/editor/optimizeImports/common/kt21515/callableReferenceOnClassWithCompanion.kt.after

@@ -0,0 +1,35 @@
+package foo
+
+import foo.CallableReferenceOnClassWithCompanion.Base.Companion.FromBaseCompanion
+import foo.CallableReferenceOnClassWithCompanion.CompanionSupertype.FromCompanionSupertype
+
+object CallableReferenceOnClassWithCompanion {
+
+    open class Base {
+        companion object {
+            class FromBaseCompanion {
+                fun foo() = 42
+
+                // We need it to cover another code-path
+                companion object
+            }
+        }
+    }
+
+    open class CompanionSupertype {
+        class FromCompanionSupertype {
+            fun foo() = 42
+
+            // We need it to cover another code-path
+            companion object
+        }
+    }
+}
+
+class Derived : CallableReferenceOnClassWithCompanion.Base() {
+    companion object : CallableReferenceOnClassWithCompanion.CompanionSupertype() { }
+
+    // Callable references
+    val c = FromBaseCompanion::foo
+    val d = FromCompanionSupertype::foo
+}

idea/testData/editor/optimizeImports/common/kt21515/callableReferenceOnObject.kt

@@ -0,0 +1,29 @@
+package foo
+
+import foo.CallableReferenceOnObject.Base.Companion.FromBaseCompanion
+import foo.CallableReferenceOnObject.CompanionSupertype.FromCompanionSupertype
+
+object CallableReferenceOnObject {
+
+    open class Base {
+        companion object {
+            object FromBaseCompanion {
+                fun foo() = 42
+            }
+        }
+    }
+
+    open class CompanionSupertype {
+        object FromCompanionSupertype {
+            fun foo() = 42
+        }
+    }
+}
+
+class Derived : CallableReferenceOnObject.Base() {
+    companion object : CallableReferenceOnObject.CompanionSupertype() { }
+
+    // Callable references
+    val c = FromBaseCompanion::foo
+    val d = FromCompanionSupertype::foo
+}

idea/testData/editor/optimizeImports/common/kt21515/callableReferenceOnObject.kt.after

@@ -0,0 +1,29 @@
+package foo
+
+import foo.CallableReferenceOnObject.Base.Companion.FromBaseCompanion
+import foo.CallableReferenceOnObject.CompanionSupertype.FromCompanionSupertype
+
+object CallableReferenceOnObject {
+
+    open class Base {
+        companion object {
+            object FromBaseCompanion {
+                fun foo() = 42
+            }
+        }
+    }
+
+    open class CompanionSupertype {
+        object FromCompanionSupertype {
+            fun foo() = 42
+        }
+    }
+}
+
+class Derived : CallableReferenceOnObject.Base() {
+    companion object : CallableReferenceOnObject.CompanionSupertype() { }
+
+    // Callable references
+    val c = FromBaseCompanion::foo
+    val d = FromCompanionSupertype::foo
+}

idea/testData/editor/optimizeImports/common/kt21515/constructor.kt

@@ -0,0 +1,30 @@
+package foo
+
+import foo.Constructors.Base.Companion.FromBaseCompanion
+import foo.Constructors.CompanionSupertype.FromCompanionSupertype
+
+object Constructors {
+
+    open class Base {
+        companion object {
+            class FromBaseCompanion {
+                fun foo() = 42
+            }
+        }
+    }
+
+    open class CompanionSupertype {
+        class FromCompanionSupertype {
+            fun foo() = 42
+        }
+    }
+}
+
+class Derived : Constructors.Base() {
+    companion object : Constructors.CompanionSupertype() {
+    }
+
+    // Constructors
+    val e = FromBaseCompanion()
+    val f = FromCompanionSupertype()
+}

idea/testData/editor/optimizeImports/common/kt21515/constructor.kt.after

@@ -0,0 +1,30 @@
+package foo
+
+import foo.Constructors.Base.Companion.FromBaseCompanion
+import foo.Constructors.CompanionSupertype.FromCompanionSupertype
+
+object Constructors {
+
+    open class Base {
+        companion object {
+            class FromBaseCompanion {
+                fun foo() = 42
+            }
+        }
+    }
+
+    open class CompanionSupertype {
+        class FromCompanionSupertype {
+            fun foo() = 42
+        }
+    }
+}
+
+class Derived : Constructors.Base() {
+    companion object : Constructors.CompanionSupertype() {
+    }
+
+    // Constructors
+    val e = FromBaseCompanion()
+    val f = FromCompanionSupertype()
+}

idea/testData/editor/optimizeImports/common/kt21515/typeReference.kt

@@ -0,0 +1,30 @@
+package foo
+
+import foo.TypeReference.Base.Companion.FromBaseCompanion
+import foo.TypeReference.CompanionSupertype.FromCompanionSupertype
+
+object TypeReference {
+
+    open class Base {
+        companion object {
+            class FromBaseCompanion {
+                fun foo() = 42
+            }
+        }
+    }
+
+    open class CompanionSupertype {
+        class FromCompanionSupertype {
+            fun foo() = 42
+        }
+    }
+}
+
+class Derived : TypeReference.Base() {
+    companion object : TypeReference.CompanionSupertype() {
+    }
+
+    // Type references
+    val a: FromBaseCompanion? = null
+    val b: FromCompanionSupertype? = null
+}

idea/testData/editor/optimizeImports/common/kt21515/typeReference.kt.after

@@ -0,0 +1,30 @@
+package foo
+
+import foo.TypeReference.Base.Companion.FromBaseCompanion
+import foo.TypeReference.CompanionSupertype.FromCompanionSupertype
+
+object TypeReference {
+
+    open class Base {
+        companion object {
+            class FromBaseCompanion {
+                fun foo() = 42
+            }
+        }
+    }
+
+    open class CompanionSupertype {
+        class FromCompanionSupertype {
+            fun foo() = 42
+        }
+    }
+}
+
+class Derived : TypeReference.Base() {
+    companion object : TypeReference.CompanionSupertype() {
+    }
+
+    // Type references
+    val a: FromBaseCompanion? = null
+    val b: FromCompanionSupertype? = null
+}