Generate toArray methods defined in classes inherited from collections as public even if they are declared with different visibility in Kotlin.

compiler/testData/codegen/box/toArray/toArrayShouldBePublic.kt

@@ -0,0 +1,50 @@
+// TARGET_BACKEND: JVM
+// WITH_RUNTIME
+
+// FILE: SingletonCollection.kt
+package test
+
+open class SingletonCollection<T>(val value: T) : AbstractCollection<T>() {
+    override val size = 1
+    override fun iterator(): Iterator<T> = listOf(value).iterator()
+
+    protected fun toArray(): Array<Any?> =
+            arrayOf<Any?>(value)
+
+    protected fun <E> toArray(a: Array<E>): Array<E> {
+        a[0] = value as E
+        return a
+    }
+}
+
+// FILE: DerivedSingletonCollection.kt
+package test2
+
+import test.*
+
+class DerivedSingletonCollection<T>(value: T) : SingletonCollection<T>(value)
+
+// FILE: box.kt
+import test.*
+import test2.*
+
+fun box(): String {
+    val sc = SingletonCollection(42)
+
+    val test1 = (sc as java.util.Collection<Int>).toArray()
+    if (test1[0] != 42) return "Failed #1"
+
+    val test2 = arrayOf<Any?>(0)
+    (sc as java.util.Collection<Int>).toArray(test2)
+    if (test2[0] != 42) return "Failed #2"
+
+    val dsc = DerivedSingletonCollection(42)
+    val test3 = (dsc as java.util.Collection<Int>).toArray()
+    if (test3[0] != 42) return "Failed #3"
+
+    val test4 = arrayOf<Any?>(0)
+    (dsc as java.util.Collection<Int>).toArray(test4)
+    if (test4[0] != 42) return "Failed #4"
+
+    return "OK"
+}