[FIR] Disallow qualified access to uninitialized fields in delegate

When using a field as the delegate for a super-interface of an object,
make sure uninitialized fields are not allowed. Specifically, disallow
access to these fields when referenced via object qualifier.

^KT-56489 Fixed

compiler/testData/diagnostics/tests/controlFlowAnalysis/fieldAsClassDelegate.fir.kt

@@ -1,5 +1,6 @@
-// See KT-15566
+// WITH_STDLIB
 // NI_EXPECTED_FILE
+// ISSUE: KT-15566, KT-56489
 
 import DefaultHttpClient.client
 
@@ -9,7 +10,7 @@ class HttpClientImpl : HttpClient
 
 // Below we should have initialization error for both (!) delegates
 
-object DefaultHttpClient : HttpClient by client {
+object DefaultHttpClient : HttpClient by <!UNINITIALIZED_VARIABLE!>client<!> {
     val client = HttpClientImpl()
 }
 
@@ -22,15 +23,10 @@ object DefaultHttpClientWithFun : HttpClient by fClient() {
 
 private fun fClient() = HttpClientImpl()
 
-private fun <T> lazy(init: () -> T): kotlin.<!UNRESOLVED_REFERENCE!>Lazy<!><T> {
-    init()
-    null!!
-}
-
 object DefaultHttpClientWithBy : HttpClient by client {
     val client by lazy { HttpClientImpl() }
 }
 
-object DefaultFqHttpClient : HttpClient by DefaultFqHttpClient.client {
+object DefaultFqHttpClient : HttpClient by <!UNINITIALIZED_VARIABLE!>DefaultFqHttpClient.client<!> {
     val client = HttpClientImpl()
 }

compiler/testData/diagnostics/tests/controlFlowAnalysis/fieldAsClassDelegate.kt

@@ -1,5 +1,6 @@
-// See KT-15566
+// WITH_STDLIB
 // NI_EXPECTED_FILE
+// ISSUE: KT-15566, KT-56489
 
 import DefaultHttpClient.client
 
@@ -22,15 +23,10 @@ object DefaultHttpClientWithFun : HttpClient by fClient() {
 
 private fun fClient() = HttpClientImpl()
 
-private fun <T> lazy(init: () -> T): kotlin.<!UNRESOLVED_REFERENCE!>Lazy<!><T> {
-    init()
-    null!!
-}
-
 object DefaultHttpClientWithBy : HttpClient by client {
     val client by lazy { HttpClientImpl() }
 }
 
 object DefaultFqHttpClient : HttpClient by DefaultFqHttpClient.<!UNINITIALIZED_VARIABLE!>client<!> {
     val client = HttpClientImpl()
-}
+}

compiler/testData/diagnostics/tests/controlFlowAnalysis/fieldAsClassDelegate.ni.txt

@@ -1,7 +1,6 @@
 package
 
 private fun fClient(): HttpClientImpl
-private fun </*0*/ T> lazy(/*0*/ init: () -> T): [Error type: Unresolved type for kotlin.Lazy<T>]<T>
 
 public object DefaultFqHttpClient : HttpClient {
     private constructor DefaultFqHttpClient()
@@ -21,7 +20,7 @@ public object DefaultHttpClient : HttpClient {
 
 public object DefaultHttpClientWithBy : HttpClient {
     private constructor DefaultHttpClientWithBy()
-    public final val client: [Error type: Error delegation type for lazy { HttpClientImpl() }]
+    public final val client: HttpClientImpl
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String