JVM_IR KT-43109 generate internal bridge for custom internal 'toArray'

Also add some tests for internal collection stubs.

compiler/testData/codegen/bytecodeListing/collectionStubs/collectionWithInternalRemove.kt

@@ -0,0 +1,9 @@
+class Test<T> : Collection<T> {
+    override val size: Int get() = TODO()
+    override fun contains(element: T): Boolean = TODO()
+    override fun containsAll(elements: Collection<T>): Boolean = TODO()
+    override fun isEmpty(): Boolean = TODO()
+    override fun iterator(): Iterator<T> = TODO()
+
+    internal fun remove(x: T): Boolean = false
+}