Experiment: Encode annotations with a specialized representation

[mbovel]

[skip ci]

[mbovel]

Currently failing tests

tests/neg/i4373.scala:

assertion failed: Ident(<error>)testOnly 36s
        at scala.runtime.Scala3RunTime$.assertFailed(Scala3RunTime.scala:8)
        at dotty.tools.dotc.core.SimpleExprs$.fromTree(SimpleExprs.scala:47)
        at dotty.tools.dotc.core.SimpleExprs$.fromTree(SimpleExprs.scala:54)
        at dotty.tools.dotc.core.SimpleExprs$.fromTree(SimpleExprs.scala:50)
        at dotty.tools.dotc.core.Annotations$Annotation$.apply(Annotations.scala:226)
        at dotty.tools.dotc.typer.TypeAssigner.assignType(TypeAssigner.scala:563)
        at dotty.tools.dotc.typer.TypeAssigner.assignType$(TypeAssigner.scala:16)
        at dotty.tools.dotc.typer.Typer.assignType(Typer.scala:148)
        at dotty.tools.dotc.typer.Typer.typedAnnotated(Typer.scala:3323)
        at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:3535)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3585)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3662)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3666)
        at dotty.tools.dotc.typer.Typer.typedType(Typer.scala:3780)
        at dotty.tools.dotc.typer.Namer.typedAheadType$$anonfun$1(Namer.scala:1762)
        at dotty.tools.dotc.typer.Namer.typedAhead(Namer.scala:1755)
        at dotty.tools.dotc.typer.Namer.typedAheadType(Namer.scala:1762)
        at dotty.tools.dotc.typer.Namer$TypeDefCompleter.typeSig(Namer.scala:1093)
        at dotty.tools.dotc.typer.Namer$Completer.completeInCreationContext(Namer.scala:990)
        at dotty.tools.dotc.typer.Namer$Completer.complete(Namer.scala:859)
        at dotty.tools.dotc.core.SymDenotations$SymDenotation.completeFrom(SymDenotations.scala:175)
        at dotty.tools.dotc.core.Denotations$Denotation.completeInfo$1(Denotations.scala:190)
        at dotty.tools.dotc.core.Denotations$Denotation.info(Denotations.scala:192)
        at dotty.tools.dotc.core.SymDenotations$SymDenotation.ensureCompleted(SymDenotations.scala:393)
        at dotty.tools.dotc.typer.Typer.retrieveSym(Typer.scala:3447)
        at dotty.tools.dotc.typer.Typer.typedNamed$1(Typer.scala:3472)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3584)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3662)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3666)
        at dotty.tools.dotc.typer.Typer.traverse$1(Typer.scala:3688)
        at dotty.tools.dotc.typer.Typer.typedStats(Typer.scala:3734)
        at dotty.tools.dotc.typer.Typer.typedClassDef(Typer.scala:3167)
        at dotty.tools.dotc.typer.Typer.typedTypeOrClassDef$1(Typer.scala:3488)

tests/neg/nowarn.scala:

Invalid message filter / Test / testOnly 68s
unknown filter: wat?
filter needs to be a compile-time constant string
filter needs to be a compile-time constant string

tests/neg/instantiateAbstract.scala:

Errors found on incorrect row numbers when compiling tests/neg/instantiateAbstract.scala
-> following the errors: Test / testOnly 127s
 at 0: Annotation is abstract; it cannot be instantiated
 at 9: Annotation is abstract; it cannot be instantiated
 at 16: Annotation is abstract; it cannot be instantiated
 at 17: Annotation is abstract; it cannot be instantiated
 at 18: Annotation is abstract; it cannot be instantiated
 at 23: AA is abstract; it cannot be instantiated
 at 25: TT is a trait; it cannot be instantiated
 at 27: A does not conform to its self type B; cannot be instantiated

tests/neg/repeatable:

-> following the errors:
 at 0: Not repeatable annotation repeated
 at 0: Container must not be present at the same time as the element it contains
 at 0: Container must not be present at the same time as the element it contains

tests/run/t6380.scala:

did not match check file. Actual output:
List(class java.lang.Exception) testOnly 265s
List(class java.lang.Throwable)
List(class java.lang.RuntimeException)
List(class java.lang.IllegalArgumentException, class java.util.NoSuchElementException)
List(class java.lang.IndexOutOfBoundsException)
List(class java.lang.IllegalStateException, class java.lang.IllegalStateException)
List(class java.lang.NullPointerException, class java.lang.NullPointerException)

tests/pos/i20901:3144/4685:

TASTy printer difference for class Foo in tests/pos/i20901/Foo.scala, did not match tests/pos/i20901/Foo.tastycheck,
  output dumped in after-printing.txt, check diff with `git diff --no-index -- tests/pos/i20901/Foo.tastycheck after-printing.txt`
  actual output:
Header:
  version: <elided>
  tooling: <elided>
     UUID: <elided>

Names (276 bytes, starting from <elided base index>):
     0: ASTs
     1: <empty>
     2: scala
     3: reflect
     4: scala[Qualified . reflect]
     5: ClassTag
     6: Foo
     7: <init>
     8: java
     9: lang
    10: java[Qualified . lang]