Fix type SeqLiteral

Author: noti0na1

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

@@ -1604,7 +1604,8 @@ class Typer extends Namer
   }
 
   def typedSeqLiteral(tree: untpd.SeqLiteral, pt: Type)(using Context): SeqLiteral = {
-    val elemProto = pt.elemType match {
+    val pt1 = if ctx.explicitNulls then pt.stripNull else pt
+    val elemProto = pt1.elemType match {
       case NoType => WildcardType
       case bounds: TypeBounds => WildcardType(bounds)
       case elemtp => elemtp
@@ -3518,6 +3519,8 @@ class Typer extends Namer
       }
 
       def tryUnsafeNullConver(fail: => Tree)(using Context): Tree =
+        // println(tree.tpe)
+        // println(pt.stripAllNulls)
         // If explicitNulls and unsafeNulls are enabled, and
         if ctx.mode.is(Mode.UnsafeNullConversion) && pt.isValueType &&
           tree.tpe.isUnsafeConvertable(pt)