Rewrite bridge generation to Kotlin, make it abstract

compiler/testData/codegen/box/bridges/complexMultiInheritance.kt

@@ -0,0 +1,25 @@
+open class A {
+    open fun foo(): Any = "A"
+}
+
+trait B : A
+
+open class C : A() {
+    override fun foo(): Int = 222
+}
+
+trait D {
+    fun foo(): Number
+}
+
+class E : B, C(), D
+
+fun box(): String {
+    val e = E()
+    if (e.foo() != 222) return "Fail 1"
+    if ((e : D).foo() != 222) return "Fail 2"
+    if ((e : C).foo() != 222) return "Fail 3"
+    if ((e : B).foo() != 222) return "Fail 4"
+    if ((e : A).foo() != 222) return "Fail 5"
+    return "OK"
+}