Revert "JS_IR: remove traces of @kotlin.native.internal.InlineConstructor"

This reverts commit a74fae246b.

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/inline/FunctionInlining.kt

@@ -19,6 +19,7 @@ import org.jetbrains.kotlin.config.languageVersionSettings
 import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.IrStatement
 import org.jetbrains.kotlin.ir.backend.js.JsIrBackendContext
+import org.jetbrains.kotlin.ir.builders.irGet
 import org.jetbrains.kotlin.ir.builders.irReturn
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.expressions.*
@@ -28,6 +29,7 @@ import org.jetbrains.kotlin.ir.symbols.impl.IrReturnableBlockSymbolImpl
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid
 import org.jetbrains.kotlin.ir.visitors.transformChildrenVoid
+import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.util.OperatorNameConventions
 
 typealias Context = JsIrBackendContext
@@ -88,7 +90,11 @@ internal class FunctionInlining(val context: Context): IrElementTransformerVoidW
         return (symbol.owner as? IrSimpleFunction)?.resolveFakeOverride() ?: symbol.owner
     }
 
-    private val IrFunction.needsInlining get() = (this.isInline && !this.isExternal)
+    private val inlineConstructor = FqName("kotlin.native.internal.InlineConstructor")
+
+    private val IrFunction.isInlineConstructor get() = annotations.hasAnnotation(inlineConstructor)
+
+    private val IrFunction.needsInlining get() = isInlineConstructor || (this.isInline && !this.isExternal)
 
     private inner class Inliner(val callSite: IrFunctionAccessExpression,
                                 val callee: IrFunction,
@@ -134,6 +140,38 @@ internal class FunctionInlining(val context: Context): IrElementTransformerVoidW
             val endOffset = callee.endOffset
             val irBuilder = context.createIrBuilder(irReturnableBlockSymbol, startOffset, endOffset)
 
+            if (callee.isInlineConstructor) {
+                // Copier sets parent to be the current function but
+                // constructor's parent cannot be a function.
+                val constructedClass = callee.parentAsClass
+                copiedCallee.parent = constructedClass
+                val delegatingConstructorCall = statements[0] as IrDelegatingConstructorCall
+                irBuilder.run {
+                    val constructorCall = IrConstructorCallImpl(
+                        startOffset, endOffset,
+                        callSite.type,
+                        delegatingConstructorCall.symbol, delegatingConstructorCall.descriptor,
+                        constructedClass.typeParameters.size, 0,
+                        delegatingConstructorCall.symbol.owner.valueParameters.size
+                    ).apply {
+                        delegatingConstructorCall.symbol.owner.valueParameters.forEach {
+                            putValueArgument(it.index, delegatingConstructorCall.getValueArgument(it.index))
+                        }
+                        constructedClass.typeParameters.forEach {
+                            putTypeArgument(it.index, delegatingConstructorCall.getTypeArgument(it.index))
+                        }
+                    }
+                    val oldThis = constructedClass.thisReceiver!!
+                    val newThis = currentScope.scope.createTemporaryVariableWithWrappedDescriptor(
+                        irExpression = constructorCall,
+                        nameHint = constructedClass.fqNameSafe.toString() + ".this"
+                    )
+                    statements[0] = newThis
+                    substituteMap[oldThis] = irGet(newThis)
+                    statements.add(irReturn(irGet(newThis)))
+                }
+            }
+
             val transformer = ParameterSubstitutor()
             statements.transform { it.transform(transformer, data = null) }
             statements.addAll(0, evaluationStatements)