JVM_IR drop StripTypeAliasDeclarationsLowering

compiler/ir/backend.jvm/lower/src/org/jetbrains/kotlin/backend/jvm/JvmLower.kt

@@ -52,12 +52,6 @@ private val validateIrAfterLowering = makeCustomPhase(
     description = "Validate IR after lowering"
 )
 
-private val stripTypeAliasDeclarationsPhase = makeIrFilePhase<CommonBackendContext>(
-    { StripTypeAliasDeclarationsLowering() },
-    name = "StripTypeAliasDeclarations",
-    description = "Strip typealias declarations"
-)
-
 // TODO make all lambda-related stuff work with IrFunctionExpression and drop this phase
 private val provisionalFunctionExpressionPhase = makeIrFilePhase<CommonBackendContext>(
     { ProvisionalFunctionExpressionLowering() },
@@ -260,7 +254,6 @@ private val kotlinNothingValueExceptionPhase = makeIrFilePhase<CommonBackendCont
 
 private val jvmFilePhases = listOf(
     typeAliasAnnotationMethodsPhase,
-    stripTypeAliasDeclarationsPhase,
     provisionalFunctionExpressionPhase,
 
     jvmOverloadsAnnotationPhase,

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/transform.kt

@@ -74,7 +74,7 @@ inline fun <T, reified S : T> MutableList<T>.transformSubsetFlat(transformation:
     when (transformed?.size) {
         null -> i++
         0 -> removeAt(i)
-        1 -> set(i++, transformed.first())
+        1 -> set(i++, transformed[0])
         else -> {
             addAll(i, transformed)
             i += transformed.size