bugfix: Fix issues after backporting

Author: tgodzik

compiler/src/dotty/tools/backend/sjs/JSCodeGen.scala

@@ -3031,7 +3031,7 @@ class JSCodeGen()(using genCtx: Context) {
       case singleDim :: Nil =>
         // Use a js.NewArray
         val arrayTypeRef = toTypeRef(arrayClassConstant.typeValue).asInstanceOf[jstpe.ArrayTypeRef]
-        js.NewArray(arrayTypeRef, genExpr(singleDim))
+        js.NewArray(arrayTypeRef, List(genExpr(singleDim)))
       case _ =>
         // Delegate to jlr.Array.newInstance
         js.ApplyStatic(js.ApplyFlags.empty, JLRArrayClassName, js.MethodIdent(JLRArrayNewInstanceMethodName),
@@ -4852,6 +4852,7 @@ class JSCodeGen()(using genCtx: Context) {
 object JSCodeGen {
 
   private val JLRArrayClassName = ClassName("java.lang.reflect.Array")
+  private val NullPointerExceptionClass = ClassName("java.lang.NullPointerException")
   private val JSObjectClassName = ClassName("scala.scalajs.js.Object")
   private val JavaScriptExceptionClassName = ClassName("scala.scalajs.js.JavaScriptException")
 

compiler/src/dotty/tools/dotc/core/Types.scala

@@ -5794,11 +5794,13 @@ object Types extends TypeUtils {
     protected def derivedLambdaType(tp: LambdaType)(formals: List[tp.PInfo], restpe: Type): Type =
       tp.derivedLambdaType(tp.paramNames, formals, restpe)
 
+    protected def mapArg(arg: Type, tparam: ParamInfo): Type = arg match
+      case arg: TypeBounds => this(arg)
+      case arg => atVariance(variance * tparam.paramVarianceSign)(this(arg))
+
     protected def mapArgs(args: List[Type], tparams: List[ParamInfo]): List[Type] = args match
       case arg :: otherArgs if tparams.nonEmpty =>
-        val arg1 = arg match
-          case arg: TypeBounds => this(arg)
-          case arg => atVariance(variance * tparams.head.paramVarianceSign)(this(arg))
+        val arg1 = mapArg(arg, tparams.head)
         val otherArgs1 = mapArgs(otherArgs, tparams.tail)
         if ((arg1 eq arg) && (otherArgs1 eq otherArgs)) args
         else arg1 :: otherArgs1

compiler/src/dotty/tools/dotc/typer/Checking.scala

@@ -40,6 +40,7 @@ import printing.Formatting.hlAsKeyword
 
 import collection.mutable
 import reporting.*
+import dotty.tools.dotc.core.TypeApplications.TypeParamInfo
 
 object Checking {
   import tpd.*

presentation-compiler/src/main/dotty/tools/pc/utils/InteractiveEnrichments.scala

@@ -281,7 +281,7 @@ object InteractiveEnrichments extends CommonMtagsEnrichments:
             sym,
             () => parentSymbols.iterator.map(toSemanticdbSymbol).toList.asJava,
             contentType,
-          )
+          ).nn
       documentation.nn.toScala
     end symbolDocumentation
   end extension