[IR] Fix file modules after actualization

When files from different IrModules are merged in IrActualizer
their IrModule link was not updated. This led to assuming them
as different modules, and incorrect internal visibility handling.

^KT-62623

compiler/testData/codegen/box/multiplatform/k2/internalOverride.kt

@@ -0,0 +1,47 @@
+// LANGUAGE: +MultiPlatformProjects
+// It accidentially passes K1 JVM while not intended to do so.
+// IGNORE_BACKEND_K1: JS, JS_IR, JS_IR_ES6, WASM, NATIVE
+// MODULE: common
+// FILE: common.kt
+
+open class A {
+    open internal fun foo() = "A"
+}
+
+open class B {
+    open internal fun foo() = "B"
+}
+
+
+// MODULE: middle()()(common)
+// FILE: middle.kt
+
+class AChild : A() {
+    override public fun foo() = "AChild"
+}
+
+open class C {
+    open internal fun foo() = "C"
+}
+
+// MODULE: main()()(middle)
+// FILE: main.kt
+
+class BChild : B() {
+    override public fun foo() = "BChild"
+}
+
+class CChild : C() {
+    override public fun foo() = "CChild"
+}
+
+
+fun box() : String {
+    val a: A = AChild()
+    val b: B = BChild()
+    val c: C = CChild()
+    if (a.foo() != "AChild") return "Fail 1"
+    if (b.foo() != "BChild") return "Fail 2"
+    if (c.foo() != "CChild") return "Fail 3"
+    return "OK"
+}