FIR IDE: enable override implement test for FIR

idea/testData/codeInsight/overrideImplement/complexMultiOverride.kt.fir.after

@@ -0,0 +1,30 @@
+open class Base<A, B, C>() {
+    open val method : (A?) -> A = { it!! }
+    open fun foo(value : B) : B = value
+    open fun bar(value : () -> C) : (String) -> C = { value() }
+}
+
+class C : Base<String, C, Unit>() {
+    override fun bar(value: () -> Unit): (String) -> Unit {
+        <selection><caret>return super.bar(value)</selection>
+    }
+
+    override fun equals(other: Any?): Boolean {
+        return super.equals(other)
+    }
+
+    override fun foo(value: C): C {
+        return super.foo(value)
+    }
+
+    override fun hashCode(): Int {
+        return super.hashCode()
+    }
+
+    override val method: (String?) -> String
+        get() = method
+
+    override fun toString(): String {
+        return super.toString()
+    }
+}