Fix initialization of object's INSTANCE$ field

Call object's constructor in <clinit> and ignore the result, but in the first
line of <init> save the current "this" to INSTANCE$

 #KT-4516 Fixed
 #KT-4543 Fixed
 #KT-5291 Fixed
 #KT-5523 Fixed
 #KT-5582 Fixed

compiler/testData/codegen/box/objects/privateFunctionFromClosureInInitializer_kt5582.kt

@@ -0,0 +1,20 @@
+trait T
+
+object Foo {
+    private fun foo(p: T) = p
+
+    private val v: Int = {
+        val x = foo(O)
+        42
+    }()
+
+    private object O : T
+
+    val result = v
+}
+
+fun box(): String {
+    val foo = Foo
+    if (foo.result != 42) return "Fail: ${foo.result}"
+    return "OK"
+}