Do not print self types of module objects

Author: nicolasstucki

compiler/src/dotty/tools/dotc/printing/RefinedPrinter.scala

@@ -652,7 +652,7 @@ class RefinedPrinter(_ctx: Context) extends PlainPrinter(_ctx) {
     val selfText = {
       val selfName = if (self.name == nme.WILDCARD) keywordStr("this") else self.name.toString
       (selfName ~ optText(self.tpt)(": " ~ _) ~ " =>").close
-    } provided !self.isEmpty
+    } provided (!self.isEmpty && !constr.symbol.owner.is(Module))
 
     val body = if (ctx.settings.YtestPickler.value) {
       // Pickling/unpickling reorders the body members, so we need to homogenize

compiler/test/dotty/tools/dotc/FromTastyTests.scala

@@ -61,7 +61,6 @@ class FromTastyTests extends ParallelTesting {
         "eff-dependent.scala",
       ),
       recompileBlacklist = Set(
-        "puzzle"
       )
     )
     step1.checkCompile() // Compile all files to generate the class files with tasty

tests/pos/simpleCaseObject.decompiled

@@ -1,6 +1,6 @@
 /** Decompiled from out/posTestFromTasty/pos/simpleCaseObject/foo/Foo.class */
 package foo {
-  case object Foo  { this: foo.Foo.type =>
+  case object Foo  {
     override def hashCode(): Int = 1045991777
     override def toString(): String = "Foo"
     override def canEqual(that: Any): Boolean =

tests/run/puzzle.decompiled

@@ -1,5 +1,5 @@
 /** Decompiled from out/runTestFromTasty/run/puzzle/Test.class */
-object Test  { this: Test.type =>
+object Test  {
   def main(args: Array[String]): Unit =
     {
       println(if false then 5.0 else 53.0)