Disable FromTasty test

I got the following difference for i0306.scala
```
<   val x: scala.AnyRef = new bar.C[scala.collection.Seq[_ >: scala.Nothing <: scala.Any]]()
---
>   val x: scala.AnyRef = new ([T >: scala.Nothing <: scala.collection.Seq[_ >: scala.Nothing <: scala.Any]] => bar.C[T])[scala.collection.Seq[_ >: scala.Nothing <: scala.Any]]()

That is, the output has eta expanded bar.C to [T] => bar.C[T]. It's not done during unpickling as far as I can see, so some code must do it afterwards.

Author: odersky

compiler/src/dotty/tools/dotc/config/Config.scala

@@ -161,7 +161,7 @@ object Config {
   final val showCompletions = false
 
   /** If set, enables tracing */
-  final val tracingEnabled = false
+  final val tracingEnabled = true
 
   /** Initial capacity of uniques HashMap.
    *  Note: This MUST BE a power of two to work with util.HashSet

compiler/test/dotc/pos-from-tasty.blacklist

@@ -27,3 +27,7 @@ t6278-synth-def.scala
 
 # Need to print empty tree for implicit match
 i5938.scala
+
+# decompiled output has an extra eta-expansion (due to dealiasing?)
+i0306.scala
+

docs/docs/reference/features-classification.md

@@ -44,8 +44,9 @@ These features replace existing constructs with the aim of making the language s
    of value classes while guaranteeing absence of boxing,
  - [Toplevel definitions](https://dotty.epfl.ch/docs/reference/dropped-features/package-objects.html) replace package objects, dropping syntactic boilerplate,
  - [Vararg patterns](https://dotty.epfl.ch/docs/reference/changed-features/vararg-patterns.html) now use the form `: _*` instead of `@ _*`, mirroring vararg expressions,
- - [Synthesized creation methods](https://contributors.scala-lang.org/t/expunging-new-from-scala-3/2868/81) allow to use simple function call syntax
- instead of `new` expressions (under discussion, not implemented).
+ - [Creator applications](https://dotty.epfl.ch/docs/reference/other-new-features/creator-applications.html) allow to use simple function call syntax
+ instead of `new` expressions. `new` expressions stay around as a fallback for
+ the cases where creator applications cannot be used.
 
 With the exception of early initializers and old-style vararg patterns, all superseded features continue to be available in Scala 3.0. The plan is to deprecate and phase them out later.
 

docs/sidebar.yml

@@ -69,6 +69,8 @@ sidebar:
           subsection:
             - title: Trait Parameters
               url: docs/reference/other-new-features/trait-parameters.html
+            - title: Creator Applications
+              url: docs/reference/other-new-features/creator-applications.html
             - title: Inlining by Rewriting
               url: docs/reference/other-new-features/inline.html
             - title: Meta Programming