Fix common supertype calculation

Use star-projections instead of 'out Any?' in corner cases

 #KT-11468 Fixed

compiler/testData/diagnostics/tests/generics/commonSupertypeContravariant.kt

@@ -0,0 +1,8 @@
+interface In<in E>
+
+class En<T> : In<T>
+class A : In<A>
+fun <T> select(x: T, y: T): T = x ?: y
+
+// Return type should be In<*> nor In<out Any?>
+fun foobar(e: En<*>) = select(A(), e)

compiler/testData/diagnostics/tests/generics/commonSupertypeContravariant.txt

@@ -0,0 +1,24 @@
+package
+
+public fun foobar(/*0*/ e: En<*>): In<*>
+public fun </*0*/ T> select(/*0*/ x: T, /*1*/ y: T): T
+
+public final class A : In<A> {
+    public constructor 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 En</*0*/ T> : In<T> {
+    public constructor En</*0*/ T>()
+    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 interface In</*0*/ in E> {
+    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
+}

compiler/testData/diagnostics/tests/generics/commonSupertypeContravariant2.kt

@@ -0,0 +1,7 @@
+interface In<in E>
+class A : In<A>
+class B : In<B>
+fun <T> select(x: T, y: T) = x ?: y
+
+// Return type should be In<*> nor In<out Any?>
+fun foobar(a: A, b: B) = select(a, b)

compiler/testData/diagnostics/tests/generics/commonSupertypeContravariant2.txt

@@ -0,0 +1,24 @@
+package
+
+public fun foobar(/*0*/ a: A, /*1*/ b: B): In<*>
+public fun </*0*/ T> select(/*0*/ x: T, /*1*/ y: T): T
+
+public final class A : In<A> {
+    public constructor 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 : In<B> {
+    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 interface In</*0*/ in E> {
+    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
+}