Partially revert "[IR] Hide constructors of implementation classes behind factory functions"

To restore binary compatibility with a compiler plugin used in
one of user projects.

#KT-66636 Fixed

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/expressions/impl/IrCompositeImpl.kt

@@ -10,47 +10,25 @@ import org.jetbrains.kotlin.ir.declarations.IrAttributeContainer
 import org.jetbrains.kotlin.ir.expressions.IrComposite
 import org.jetbrains.kotlin.ir.expressions.IrStatementOrigin
 import org.jetbrains.kotlin.ir.types.IrType
-import org.jetbrains.kotlin.ir.util.IrElementConstructorIndicator
 
-class IrCompositeImpl internal constructor(
-    @Suppress("UNUSED_PARAMETER")
-    constructorIndicator: IrElementConstructorIndicator?,
+class IrCompositeImpl(
     override val startOffset: Int,
     override val endOffset: Int,
     override var type: IrType,
-    override var origin: IrStatementOrigin?,
+    override var origin: IrStatementOrigin? = null,
 ) : IrComposite() {
     override val statements: MutableList<IrStatement> = ArrayList(2)
 
     override var attributeOwnerId: IrAttributeContainer = this
     override var originalBeforeInline: IrAttributeContainer? = null
-}
 
-fun IrCompositeImpl(
-    startOffset: Int,
-    endOffset: Int,
-    type: IrType,
-    origin: IrStatementOrigin? = null,
-) = IrCompositeImpl(
-    constructorIndicator = null,
-    startOffset = startOffset,
-    endOffset = endOffset,
-    type = type,
-    origin = origin,
-)
-
-fun IrCompositeImpl(
+    constructor(
         startOffset: Int,
         endOffset: Int,
         type: IrType,
         origin: IrStatementOrigin?,
         statements: List<IrStatement>,
-) = IrCompositeImpl(
-    constructorIndicator = null,
-    startOffset = startOffset,
-    endOffset = endOffset,
-    type = type,
-    origin = origin,
-).apply {
+    ) : this(startOffset, endOffset, type, origin) {
         this.statements.addAll(statements)
     }
+}

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/expressions/impl/IrReturnImpl.kt

@@ -10,32 +10,14 @@ import org.jetbrains.kotlin.ir.expressions.IrExpression
 import org.jetbrains.kotlin.ir.expressions.IrReturn
 import org.jetbrains.kotlin.ir.symbols.IrReturnTargetSymbol
 import org.jetbrains.kotlin.ir.types.IrType
-import org.jetbrains.kotlin.ir.util.IrElementConstructorIndicator
 
-class IrReturnImpl internal constructor(
-    @Suppress("UNUSED_PARAMETER")
-    constructorIndicator: IrElementConstructorIndicator?,
+class IrReturnImpl(
     override val startOffset: Int,
     override val endOffset: Int,
     override var type: IrType,
     override var returnTargetSymbol: IrReturnTargetSymbol,
-    override var value: IrExpression,
+    override var value: IrExpression
 ) : IrReturn() {
     override var attributeOwnerId: IrAttributeContainer = this
     override var originalBeforeInline: IrAttributeContainer? = null
 }
-
-fun IrReturnImpl(
-    startOffset: Int,
-    endOffset: Int,
-    type: IrType,
-    returnTargetSymbol: IrReturnTargetSymbol,
-    value: IrExpression,
-) = IrReturnImpl(
-    constructorIndicator = null,
-    startOffset = startOffset,
-    endOffset = endOffset,
-    type = type,
-    returnTargetSymbol = returnTargetSymbol,
-    value = value,
-)