[Test] KT-61360: add tests for the IrFakeOverrideBuilder

Add tests for fake overrides with focus on java interoperability

Co-authored-by: Aleksandra Arsenteva <aleksandra.arsenteva@jetbrains.com>

compiler/testData/ir/irText/fakeOverrides/collections/map/mapOverrideOnKJ.kt

@@ -0,0 +1,40 @@
+// TARGET_BACKEND: JVM
+// FULL_JDK
+// WITH_STDLIB
+// SEPARATE_SIGNATURE_DUMP_FOR_K2
+// ^ ISSUE: KT-65667
+
+// FILE: 1.kt
+import java.util.SortedMap
+
+abstract class A : SortedMap<Boolean, Boolean>
+
+abstract class B(override val values: MutableCollection<Boolean>, override val size: Int) : SortedMap<Boolean, Boolean> {
+    override fun remove(key: Boolean?): Boolean? {
+        return true
+    }
+
+    override fun get(key: Boolean?): Boolean? {
+        return true
+    }
+}
+
+
+fun test(a: A, b: B) {
+    a.size
+    a[true] = true
+    a[null] = null
+    a.get(true)
+    a.get(null)
+    a.remove(null)
+    a.remove(true)
+
+    b.size
+    b.values
+    b[false] = false
+    b[null] = null
+    b.remove(null)
+    b.remove(true)
+    b.get(null)
+    b.get(true)
+}