Introduce new type checker.

compiler/testData/diagnostics/tests/subtyping/javaAndKotlinSuperType.kt

@@ -0,0 +1,42 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+// FILE: A.java
+public interface A<T> {
+}
+
+// FILE: B.java
+public class B implements A<String> {
+}
+
+// FILE: 1.kt
+class C: B()
+
+class D: B(), A<String>
+class E: B(), A<String?>
+
+fun eatAString(a: A<String>) {}
+fun eatAStringN(a: A<String?>) {}
+
+fun test(b: B, c: C, d: D, e: E) {
+    eatAString(b)
+    eatAString(c)
+    eatAString(d)
+    eatAString(<!TYPE_MISMATCH!>e<!>)
+
+    eatAStringN(b)
+    eatAStringN(c)
+    eatAStringN(<!TYPE_MISMATCH!>d<!>)
+    eatAStringN(e)
+}
+
+// FILE: 3.kt
+
+interface X : A<String>
+interface Y: X
+interface Z: X
+
+class W: B(), Z
+
+fun test2(w: W) {
+    eatAString(w)
+    eatAStringN(<!TYPE_MISMATCH!>w<!>)
+}

compiler/testData/diagnostics/tests/subtyping/javaAndKotlinSuperType.txt

@@ -0,0 +1,65 @@
+package
+
+public fun eatAString(/*0*/ a: A<kotlin.String>): kotlin.Unit
+public fun eatAStringN(/*0*/ a: A<kotlin.String?>): kotlin.Unit
+public fun test(/*0*/ b: B, /*1*/ c: C, /*2*/ d: D, /*3*/ e: E): kotlin.Unit
+public fun test2(/*0*/ w: W): kotlin.Unit
+
+public interface A</*0*/ T : kotlin.Any!> {
+    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 open class B : A<kotlin.String!> {
+    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 class C : B {
+    public constructor C()
+    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 D : B, A<kotlin.String> {
+    public constructor D()
+    public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class E : B, A<kotlin.String?> {
+    public constructor E()
+    public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class W : B, Z {
+    public constructor W()
+    public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface X : A<kotlin.String> {
+    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 Y : X {
+    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 Z : X {
+    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
+}