[JS IR BE] Support tailreq in JS

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/TailrecLowering.kt

@@ -53,7 +53,7 @@ private fun lowerTailRecursionCalls(context: BackendContext, irFunction: IrFunct
     irFunction.body = builder.irBlockBody {
         // Define variables containing current values of parameters:
         val parameterToVariable = parameters.associate {
-            it to irTemporaryVar(irGet(it), nameHint = it.symbol.suggestVariableName())
+            it to irTemporaryVar(irGet(it), nameHint = it.symbol.suggestVariableName(), parent = irFunction)
         }
         // (these variables are to be updated on any tail call).
 
@@ -65,7 +65,7 @@ private fun lowerTailRecursionCalls(context: BackendContext, irFunction: IrFunct
                 // Read variables containing current values of parameters:
                 val parameterToNew = parameters.associate {
                     val variable = parameterToVariable[it]!!
-                    it to irTemporary(irGet(variable), nameHint = it.symbol.suggestVariableName())
+                    it to irTemporary(irGet(variable), nameHint = it.symbol.suggestVariableName()).also { it.parent = irFunction }
                 }
 
                 val transformer = BodyTransformer(

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/compiler.kt

@@ -105,6 +105,7 @@ private fun JsIrBackendContext.performInlining(moduleFragment: IrModuleFragment)
 
 private fun JsIrBackendContext.lower(moduleFragment: IrModuleFragment, dependencies: List<IrModuleFragment>) {
     moduleFragment.files.forEach(ThrowableSuccessorsLowering(this)::lower)
+    moduleFragment.files.forEach(TailrecLowering(this)::runOnFilePostfix)
     moduleFragment.files.forEach(UnitMaterializationLowering(this)::lower)
     moduleFragment.files.forEach(EnumClassLowering(this)::runOnFilePostfix)
     moduleFragment.files.forEach(EnumUsageLowering(this)::lower)