Try to not add a transformer

Author: noti0na1

compiler/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala

@@ -1194,6 +1194,10 @@ class TreeUnpickler(reader: TastyReader,
                 res.withAttachment(SuppressedApplyToNone, ())
               else res
 
+      def simplifyLub(tree: Tree): Tree =
+        tree.overwriteType(tree.tpe.simplified)
+        tree
+
       def readLengthTerm(): Tree = {
         val end = readEnd()
         val result =
@@ -1232,34 +1236,37 @@ class TreeUnpickler(reader: TastyReader,
               val expansion = exprReader.readTerm() // need bindings in scope, so needs to be read before
               Inlined(call, bindings, expansion)
             case IF =>
-              if (nextByte == INLINE) {
-                readByte()
-                InlineIf(readTerm(), readTerm(), readTerm())
-              }
-              else
-                If(readTerm(), readTerm(), readTerm())
+              simplifyLub(
+                if (nextByte == INLINE) {
+                  readByte()
+                  InlineIf(readTerm(), readTerm(), readTerm())
+                }
+                else
+                  If(readTerm(), readTerm(), readTerm()))
             case LAMBDA =>
               val meth = readTerm()
               val tpt = ifBefore(end)(readTpt(), EmptyTree)
               Closure(Nil, meth, tpt)
             case MATCH =>
-              if (nextByte == IMPLICIT) {
-                readByte()
-                InlineMatch(EmptyTree, readCases(end))
-              }
-              else if (nextByte == INLINE) {
-                readByte()
-                InlineMatch(readTerm(), readCases(end))
-              }
-              else Match(readTerm(), readCases(end))
+              simplifyLub(
+                if (nextByte == IMPLICIT) {
+                  readByte()
+                  InlineMatch(EmptyTree, readCases(end))
+                }
+                else if (nextByte == INLINE) {
+                  readByte()
+                  InlineMatch(readTerm(), readCases(end))
+                }
+                else Match(readTerm(), readCases(end)))
             case RETURN =>
               val from = readSymRef()
               val expr = ifBefore(end)(readTerm(), EmptyTree)
               Return(expr, Ident(from.termRef))
             case WHILE =>
               WhileDo(readTerm(), readTerm())
             case TRY =>
-              Try(readTerm(), readCases(end), ifBefore(end)(readTerm(), EmptyTree))
+              simplifyLub(
+                Try(readTerm(), readCases(end), ifBefore(end)(readTerm(), EmptyTree)))
             case SELECTouter =>
               val levels = readNat()
               readTerm().outerSelect(levels, SkolemType(readType()))

compiler/src/dotty/tools/dotc/transform/Pickler.scala

@@ -137,7 +137,7 @@ class Pickler extends Phase {
       }
     pickling.println("************* entered toplevel ***********")
     for ((cls, unpickler) <- unpicklers) {
-      val unpickled = typeSimplifier.transform(unpickler.rootTrees)
+      val unpickled = unpickler.rootTrees
       testSame(i"$unpickled%\n%", beforePickling(cls), cls)
     }
   }