this used as a type in a type match crashes the compiler (parser stability)

[sir-wabbit]

minimized code

trait A {
    val a: Int match { case Int => this }
}

Stack trace

-- [E036] Syntax Error: testing/Test.scala:2:35 --------------------------------
2 |    val a: Int match { case Int => this }
  |                                   ^^^^
  |            Expected an additional member selection after the keyword this

longer explanation available when compiling with `-explain`
exception occurred while typechecking testing/Test.scala
exception occurred while compiling testing/Test.scala
scala.MatchError: ThisType(TypeRef(ThisType(TypeRef(NoPrefix,module class <empty>)),trait A)) (of class dotty.tools.dotc.core.Types$CachedThisType) while compiling testing/Test.scala
Exception in thread "main" scala.MatchError: ThisType(TypeRef(ThisType(TypeRef(NoPrefix,module class <empty>)),trait A)) (of class dotty.tools.dotc.core.Types$CachedThisType)
	at dotty.tools.dotc.core.TrackingTypeComparer.matchCase$1(TypeComparer.scala:2463)
	at dotty.tools.dotc.core.TrackingTypeComparer.recur$1(TypeComparer.scala:2487)
	at dotty.tools.dotc.core.TrackingTypeComparer.matchCases(TypeComparer.scala:2508)
	at dotty.tools.dotc.core.Types$MatchType.liftedTree1$1(Types.scala:4022)
	at dotty.tools.dotc.core.Types$MatchType.reduced(Types.scala:4027)
	at dotty.tools.dotc.core.Types$MatchType.tryNormalize(Types.scala:3985)
	at dotty.tools.dotc.core.TypeOps.simplify(TypeOps.scala:153)
	at dotty.tools.dotc.core.Contexts$Context.simplify(Contexts.scala:75)
	at dotty.tools.dotc.core.Types$Type.simplified(Types.scala:1643)
	at dotty.tools.dotc.typer.Typer.simplify(Typer.scala:2192)
	at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:2179)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2213)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2225)
	at dotty.tools.dotc.typer.Namer.typedAheadType$$anonfun$1(Namer.scala:1260)
	at dotty.tools.dotc.typer.Namer.typedAhead(Namer.scala:1253)
	at dotty.tools.dotc.typer.Namer.typedAheadType(Namer.scala:1260)
	at dotty.tools.dotc.typer.Namer.valOrDefDefSig(Namer.scala:1449)
	at dotty.tools.dotc.typer.Namer$Completer.typeSig(Namer.scala:811)
	at dotty.tools.dotc.typer.Namer$Completer.completeInCreationContext(Namer.scala:935)
	at dotty.tools.dotc.typer.Namer$Completer.complete(Namer.scala:843)
	at dotty.tools.dotc.core.SymDenotations$SymDenotation.completeFrom(SymDenotations.scala:258)
	at dotty.tools.dotc.core.Denotations$Denotation.completeInfo$1(Denotations.scala:185)
	at dotty.tools.dotc.core.Denotations$Denotation.info(Denotations.scala:187)
	at dotty.tools.dotc.core.SymDenotations$SymDenotation.ensureCompleted(SymDenotations.scala:398)
	at dotty.tools.dotc.typer.Typer.retrieveSym(Typer.scala:2071)
	at dotty.tools.dotc.typer.Typer.typedNamed$1(Typer.scala:2096)
	at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:2176)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2213)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2225)
	at dotty.tools.dotc.typer.Typer.traverse$1(Typer.scala:2247)
	at dotty.tools.dotc.typer.Typer.typedStats(Typer.scala:2291)
	at dotty.tools.dotc.typer.Typer.typedClassDef(Typer.scala:1784)
	at dotty.tools.dotc.typer.Typer.typedNamed$1(Typer.scala:2109)
	at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:2176)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2213)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2225)
	at dotty.tools.dotc.typer.Typer.traverse$1(Typer.scala:2247)
	at dotty.tools.dotc.typer.Typer.typedStats(Typer.scala:2291)
	at dotty.tools.dotc.typer.Typer.typedPackageDef(Typer.scala:1910)
	at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:2150)
	at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:2177)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2213)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2225)
	at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:2333)
	at dotty.tools.dotc.typer.FrontEnd.liftedTree1$2(FrontEnd.scala:78)
	at dotty.tools.dotc.typer.FrontEnd.typeCheck$$anonfun$1(FrontEnd.scala:83)
	at dotty.runtime.function.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:12)
	at dotty.tools.dotc.typer.FrontEnd.monitor(FrontEnd.scala:42)
	at dotty.tools.dotc.typer.FrontEnd.typeCheck(FrontEnd.scala:84)
	at dotty.tools.dotc.typer.FrontEnd.runOn$$anonfun$3(FrontEnd.scala:114)
	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.immutable.List.foreach(List.scala:305)
	at dotty.tools.dotc.typer.FrontEnd.runOn(FrontEnd.scala:114)
	at dotty.tools.dotc.Run.runPhases$4$$anonfun$4(Run.scala:161)
	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.ArrayOps$.foreach$extension(ArrayOps.scala:1323)
	at dotty.tools.dotc.Run.runPhases$5(Run.scala:171)
	at dotty.tools.dotc.Run.compileUnits$$anonfun$1(Run.scala:179)
	at dotty.runtime.function.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:12)
	at dotty.tools.dotc.util.Stats$.maybeMonitored(Stats.scala:65)
	at dotty.tools.dotc.Run.compileUnits(Run.scala:186)
	at dotty.tools.dotc.Run.compileSources(Run.scala:123)
	at dotty.tools.dotc.Run.compile(Run.scala:106)
	at dotty.tools.dotc.Driver.doCompile(Driver.scala:36)
	at dotty.tools.dotc.Driver.process(Driver.scala:189)
	at dotty.tools.dotc.Driver.process(Driver.scala:158)
	at dotty.tools.dotc.Driver.process(Driver.scala:170)
	at dotty.tools.dotc.Driver.main(Driver.scala:197)
	at dotty.tools.dotc.Main.main(Main.scala)