CommonSupertypes support for flexible types

compiler/testData/diagnostics/tests/platformTypes/methodCall/inferenceWithBound.kt

@@ -0,0 +1,41 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+// FILE: p/Super.java
+
+package p;
+
+public interface Super {
+
+}
+
+// FILE: p/Sub.java
+
+package p;
+
+public interface Sub extends Super {}
+
+// FILE: p/Other.java
+
+package p;
+
+import java.util.*;
+
+public class Other {
+
+    public static Sub sub;
+
+    public static Collection<Sub> subs;
+    public static Collection<Super> supers;
+}
+
+// FILE: k.kt
+
+import p.*
+
+fun test() {
+    val col = if (1 < 2) Other.subs else Other.supers
+    col.foo()
+}
+
+fun <T: Super> Collection<T>.foo(): T = null!!
+fun listOf<T>(t: T): List<T> = null!!