A new kind of synthetic accessors for backing fields, if accessed inside lambda / object literal / local class #KT-9657 Fixed

A set of tests provided
Also #KT-4867 Fixed
Also #KT-8750 Fixed
Slight codegen refactoring

compiler/testData/codegen/box/properties/classArtificialFieldInsideNested.kt

@@ -0,0 +1,15 @@
+abstract class Your {
+    abstract val your: String
+
+    fun foo() = your
+}
+
+class My {
+    val back = "O"
+    val my: String
+        get() = object : Your() {
+            override val your = back
+        }.foo() + "K"
+}
+
+fun box() = My().my

compiler/testData/codegen/box/properties/classFieldInsideLambda.kt

@@ -0,0 +1,6 @@
+class My {
+    val my: String = "O"
+        get() = { field }() + "K"
+}
+
+fun box() = My().my

compiler/testData/codegen/box/properties/classFieldInsideLocalInSetter.kt

@@ -0,0 +1,18 @@
+class My {
+    var my: String = "U"
+        get() = { field }()
+        set(arg) {
+            class Local {
+                fun foo() {
+                    field = arg + "K"
+                }
+            }
+            Local().foo()
+        }
+}
+
+fun box(): String {
+    val m = My()
+    m.my = "O"
+    return m.my
+}

compiler/testData/codegen/box/properties/classFieldInsideNested.kt

@@ -0,0 +1,14 @@
+abstract class Your {
+    abstract val your: String
+
+    fun foo() = your
+}
+
+class My {
+    val my: String = "O"
+        get() = object : Your() {
+            override val your = field
+        }.foo() + "K"
+}
+
+fun box() = My().my

compiler/testData/codegen/box/properties/classPrivateArtificialFieldInsideNested.kt

@@ -0,0 +1,15 @@
+abstract class Your {
+    abstract val your: String
+
+    fun foo() = your
+}
+
+class My {
+    private val back = "O"
+    val my: String
+        get() = object : Your() {
+            override val your = back
+        }.foo() + "K"
+}
+
+fun box() = My().my

compiler/testData/codegen/box/properties/companionFieldInsideLambda.kt

@@ -0,0 +1,8 @@
+class My {
+    companion object {
+        val my: String = "O"
+            get() = { field }() + "K"
+    }
+}
+
+fun box() = My.my

compiler/testData/codegen/box/properties/fieldInsideLambda.kt

@@ -0,0 +1,4 @@
+val my: String = "O"
+    get() = { field }() + "K"
+
+fun box() = my