Drop traits with required classes

#KT-4771 Rejected

js/js.translator/testData/examples/cases/diamondInheritance.kt

@@ -1,26 +0,0 @@
-// Changed when traits were introduced. May not make sense any more
-
-open class Base() {
-    public var v: Int = 0
-}
-
-open class Left() : Base() {
-}
-trait Right : Base {
-}
-
-class D() : Left(), Right
-
-fun vl(l: Left): Int = l.v
-fun vr(r: Right): Int = r.v
-
-fun box(): String {
-    val d = D()
-    d.v = 42
-
-    if (d.v != 42) return "Fail #1"
-    if (vl(d) != 42) return "Fail #2"
-    if (vr(d) != 42) return "Fail #3"
-
-    return "OK"
-}

js/js.translator/testData/inheritance/cases/crazyInheritance.kt

@@ -1,56 +0,0 @@
-package foo
-
-open class A {
-    open fun f1() = "A1"
-    open fun f2() = "A2"
-    open fun f3() = "A3"
-    open fun f4() = "A4"
-
-    fun getSum(): String {
-        return "${f1()}|${f2()}|${f3()}|${f4()}"
-    }
-}
-
-trait T : A {
-    override fun f1() = "T1"
-    override fun f2() = "T2"
-}
-
-trait B : A {
-    override fun f1() = "B1"
-    override fun f3() = "B3"
-}
-
-trait N : B, T {
-    override fun f1() = "N1"
-}
-
-trait X {
-    fun f4() = "X4"
-}
-
-class C : A(), N, X {
-    override fun f4() = "C4"
-}
-
-fun box(): String {
-    val a = A()
-    val t = object : T, A() {
-    }
-    val b = object : B, A() {
-    }
-    val n = object : N, A() {
-    }
-    val x = object : X {
-    }
-    val c = C()
-
-    if (a.getSum() != "A1|A2|A3|A4") return "Bad a.getSum(), it: ${a.getSum()}"
-    if (t.getSum() != "T1|T2|A3|A4") return "Bad t.getSum(), it: ${t.getSum()}"
-    if (b.getSum() != "B1|A2|B3|A4") return "Bad b.getSum(), it: ${b.getSum()}"
-    if (n.getSum() != "N1|T2|B3|A4") return "Bad n.getSum(), it: ${n.getSum()}"
-    if (c.getSum() != "N1|T2|B3|C4") return "Bad c.getSum(), it: ${c.getSum()}"
-
-    if (x.f4() != "X4") return "Bad x.f4(), it: ${x.f4()}"
-    return "OK"
-}