[Commonizer] Implement two phased re-approximation

^KT-48288

native/commonizer/src/org/jetbrains/kotlin/commonizer/facade.kt

@@ -65,14 +65,11 @@ internal fun commonizeTarget(
 
         InlineTypeAliasCirNodeTransformer(parameters.storageManager, classifiers).invoke(mergedTree)
 
-        /*
         ReApproximationCirNodeTransformer(
             parameters.storageManager, classifiers,
             SignatureBuildingContextProvider(classifiers, typeAliasInvariant = true, skipArguments = false)
         ).invoke(mergedTree)
 
-         */
-
         ReApproximationCirNodeTransformer(
             parameters.storageManager, classifiers,
             SignatureBuildingContextProvider(classifiers, typeAliasInvariant = true, skipArguments = true)

native/commonizer/src/org/jetbrains/kotlin/commonizer/transformer/ReApproximationCirNodeTransformer.kt

@@ -68,7 +68,11 @@ internal class ReApproximationCirNodeTransformer(
             buildFunctionNode(storageManager, parent.targetDeclarations.size, classifiers, ParentNode(parent))
         }
 
-        newNode.targetDeclarations.setIfAbsent(index, functionAtIndex)
+        // Move declaration
+        if (newNode.targetDeclarations[index] == null) {
+            function.targetDeclarations[index] = null
+            newNode.targetDeclarations[index] = functionAtIndex
+        }
     }
 
     private operator fun invoke(parent: CirNodeWithMembers<*, *>, property: CirPropertyNode, index: Int, context: CirMemberContext) {
@@ -81,7 +85,11 @@ internal class ReApproximationCirNodeTransformer(
             buildPropertyNode(storageManager, parent.targetDeclarations.size, classifiers, ParentNode(parent))
         }
 
-        newNode.targetDeclarations.setIfAbsent(index, propertyAtIndex)
+        // Move declaration
+        if (newNode.targetDeclarations[index] == null) {
+            property.targetDeclarations[index] = null
+            newNode.targetDeclarations[index] = propertyAtIndex
+        }
     }
 
     private operator fun invoke(
@@ -98,6 +106,10 @@ internal class ReApproximationCirNodeTransformer(
             buildClassConstructorNode(storageManager, parent.targetDeclarations.size, classifiers, ParentNode(parent))
         }
 
-        newNode.targetDeclarations.setIfAbsent(index, constructorAtIndex)
+        // Move declaration
+        if (newNode.targetDeclarations[index] == null) {
+            constructor.targetDeclarations[index] = null
+            newNode.targetDeclarations[index] = constructorAtIndex
+        }
     }
 }

native/commonizer/src/org/jetbrains/kotlin/commonizer/tree/mergeCirTree.kt

@@ -87,7 +87,7 @@ internal fun CirNodeWithMembers<*, *>.buildFunction(
         buildFunctionNode(context.storageManager, context.targets, context.classifiers, ParentNode(parent))
     }
     /* Multiple type substitutions could in result in the same commonization result */
-    functionNode.targetDeclarations.setIfAbsent(context.targetIndex, function)
+    functionNode.targetDeclarations.set(context.targetIndex, function)
 }
 
 internal fun CirNodeWithMembers<*, *>.buildProperty(
@@ -99,7 +99,7 @@ internal fun CirNodeWithMembers<*, *>.buildProperty(
         buildPropertyNode(context.storageManager, context.targets, context.classifiers, ParentNode(parent))
     }
     /* Multiple type substitutions could in result in the same commonization result */
-    propertyNode.targetDeclarations.setIfAbsent(context.targetIndex, property)
+    propertyNode.targetDeclarations.set(context.targetIndex, property)
 }
 
 internal fun CirClassNode.buildConstructor(
@@ -111,7 +111,7 @@ internal fun CirClassNode.buildConstructor(
         buildClassConstructorNode(context.storageManager, context.targets, context.classifiers, ParentNode(parent))
     }
     /* Multiple type substitutions could in result in the same commonization result */
-    constructorNode.targetDeclarations.setIfAbsent(context.targetIndex, constructor)
+    constructorNode.targetDeclarations.set(context.targetIndex, constructor)
 }
 
 internal fun CirPackageNode.buildTypeAlias(context: TargetBuildingContext, treeTypeAlias: CirTreeTypeAlias) {

native/commonizer/src/org/jetbrains/kotlin/commonizer/utils/commonizedGroup.kt

@@ -31,8 +31,4 @@ class CommonizedGroup<T : Any>(
 
         elements[index] = value
     }
-
-    fun setIfAbsent(index: Int, value: T?) {
-        if (this[index] == null) set(index, value)
-    }
 }