IR/Android: initialize the findViewById cache before super()

In general, calling open methods in open class constructors is unsafe
because their overrides will see an uninitialized instance. This change
makes it at least possible to use the view cache in such cases.

^KT-50627 Fixed

plugins/android-extensions/android-extensions-compiler/testData/codegen/android/singleFile/0.kt

@@ -19,7 +19,7 @@ class R {
     }
 }
 
-class MyActivity(): Activity() {
+open class MyActivity(): Activity() {
     val textViewWidget = TextView(this)
     val editTextWidget = EditText(this)
     val buttonWidget = Button(this)
@@ -33,20 +33,23 @@ class MyActivity(): Activity() {
         } as T?
     }
 
-    private val textViewString = textView1.toString()
+    open fun findPasswordWidget(): View = null!!
 
-    public fun box(): String {
-        val result = when {
-            textViewString == "TextView" && password.toString() == "EditText" && login.toString() == "Button" -> "OK"
-            else -> ""
-        }
+    private val textViewReadInInit = textView1
+    private val passwordReadThroughOverride = findPasswordWidget()
 
-        clearFindViewByIdCache()
+    private fun check(expect: String, actual: String) =
+        if (expect != actual) "'$actual' != '$expect'" else null
 
-        return result
-    }
+    public fun box(): String =
+        check("Button", login.toString())
+            ?: check("TextView", textViewReadInInit.toString())
+            ?: check("EditText", passwordReadThroughOverride.toString())
+            ?: "OK".also { clearFindViewByIdCache() }
 }
 
-fun box(): String {
-    return MyActivity().box()
+class MyActivity2 : MyActivity() {
+    override fun findPasswordWidget() = password
 }
+
+fun box(): String = MyActivity2().box()