Prohibit inheritance by delegation in expect classes

#KT-20431 Fixed

compiler/testData/diagnostics/tests/multiplatform/headerClass/inheritanceByDelegationInExpectClass.kt

@@ -0,0 +1,10 @@
+// !LANGUAGE: +MultiPlatformProjects
+// MODULE: m1-common
+// FILE: common.kt
+
+interface A
+
+class B : A
+expect class Foo(b: B) : <!IMPLEMENTATION_BY_DELEGATION_IN_EXPECT_CLASS!>A by b<!>
+
+expect class Bar : <!IMPLEMENTATION_BY_DELEGATION_IN_EXPECT_CLASS!>A by B()<!>

compiler/testData/diagnostics/tests/multiplatform/headerClass/inheritanceByDelegationInExpectClass.txt

@@ -0,0 +1,27 @@
+package
+
+public interface A {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class B : A {
+    public constructor B()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final expect class Bar : A {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final expect class Foo : A {
+    public constructor Foo(/*0*/ b: B)
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}