Quote local classes crashes compiler

[liufengyun]

minimized code

import quoted._

def foo() given QuoteContext = {
  class C
  '[C]
}

Stack trace

java.lang.AssertionError: assertion failed: unresolved symbols: class C(line 10) when pickling examples/i6263.scala while compiling examples/i6263.scala
Exception in thread "main" java.lang.AssertionError: assertion failed: unresolved symbols: class C(line 10) when pickling examples/i6263.scala
	at dotty.DottyPredef$.assertFail(DottyPredef.scala:16)
	at dotty.tools.dotc.core.tasty.TreePickler.pickle(TreePickler.scala:695)
	at dotty.tools.dotc.core.quoted.PickledQuotes$.pickle(PickledQuotes.scala:90)
	at dotty.tools.dotc.core.quoted.PickledQuotes$.pickleQuote(PickledQuotes.scala:32)
	at dotty.tools.dotc.transform.ReifyQuotes$QuoteReifier.pickleAsTasty$1(ReifyQuotes.scala:237)
	at dotty.tools.dotc.transform.ReifyQuotes$QuoteReifier.pickledQuote(ReifyQuotes.scala:245)
	at dotty.tools.dotc.transform.ReifyQuotes$QuoteReifier.transformQuotation(ReifyQuotes.scala:195)
	at dotty.tools.dotc.transform.TreeMapWithStages.transform(TreeMapWithStages.scala:94)
	at dotty.tools.dotc.transform.ReifyQuotes$QuoteReifier.transform(ReifyQuotes.scala:409)
	at dotty.tools.dotc.ast.Trees$Instance$TreeMap.transform(Trees.scala:1269)
	at dotty.tools.dotc.ast.TreeMapWithImplicits.transform(TreeMapWithImplicits.scala:118)
	at dotty.tools.dotc.transform.TreeMapWithStages.mapOverTree$1(TreeMapWithStages.scala:77)
	at dotty.tools.dotc.transform.TreeMapWithStages.transform(TreeMapWithStages.scala:127)
	at dotty.tools.dotc.transform.ReifyQuotes$QuoteReifier.transform(ReifyQuotes.scala:409)
	at dotty.tools.dotc.ast.Trees$Instance$TreeMap.transform(Trees.scala:1275)
	at dotty.tools.dotc.ast.TreeMapWithImplicits.transform(TreeMapWithImplicits.scala:90)
	at dotty.tools.dotc.transform.TreeMapWithStages.mapOverTree$1(TreeMapWithStages.scala:77)
	at dotty.tools.dotc.transform.TreeMapWithStages.transform(TreeMapWithStages.scala:106)
	at dotty.tools.dotc.transform.ReifyQuotes$QuoteReifier.transform(ReifyQuotes.scala:409)
	at dotty.tools.dotc.ast.TreeMapWithImplicits.transform(TreeMapWithImplicits.scala:98)
	at dotty.tools.dotc.transform.TreeMapWithStages.mapOverTree$1(TreeMapWithStages.scala:77)
	at dotty.tools.dotc.transform.TreeMapWithStages.transform(TreeMapWithStages.scala:127)
	at dotty.tools.dotc.transform.ReifyQuotes$QuoteReifier.transform(ReifyQuotes.scala:409)
	at dotty.tools.dotc.ast.TreeMapWithImplicits.traverse$1(TreeMapWithImplicits.scala:52)
	at dotty.tools.dotc.ast.TreeMapWithImplicits.transformStats(TreeMapWithImplicits.scala:59)
	at dotty.tools.dotc.ast.TreeMapWithImplicits.transform(TreeMapWithImplicits.scala:109)
	at dotty.tools.dotc.transform.TreeMapWithStages.mapOverTree$1(TreeMapWithStages.scala:77)
	at dotty.tools.dotc.transform.TreeMapWithStages.transform(TreeMapWithStages.scala:127)
	at dotty.tools.dotc.transform.ReifyQuotes$QuoteReifier.transform(ReifyQuotes.scala:409)
	at dotty.tools.dotc.ast.Trees$Instance$TreeMap.transform(Trees.scala:1331)
	at dotty.tools.dotc.ast.TreeMapWithImplicits.transform(TreeMapWithImplicits.scala:102)
	at dotty.tools.dotc.transform.TreeMapWithStages.mapOverTree$1(TreeMapWithStages.scala:77)
	at dotty.tools.dotc.transform.TreeMapWithStages.transform(TreeMapWithStages.scala:127)
	at dotty.tools.dotc.transform.ReifyQuotes$QuoteReifier.transform(ReifyQuotes.scala:409)
	at dotty.tools.dotc.ast.Trees$Instance$TreeMap.transform$$anonfun$2(Trees.scala:1351)
	at scala.collection.immutable.List.mapConserve(List.scala:179)
	at dotty.tools.dotc.ast.Trees$Instance$TreeMap.transform(Trees.scala:1351)
	at dotty.tools.dotc.ast.Trees$Instance$TreeMap.transformStats(Trees.scala:1349)
	at dotty.tools.dotc.ast.Trees$Instance$TreeMap.transform(Trees.scala:1337)
	at dotty.tools.dotc.ast.TreeMapWithImplicits.transform(TreeMapWithImplicits.scala:102)
	at dotty.tools.dotc.transform.TreeMapWithStages.mapOverTree$1(TreeMapWithStages.scala:77)
	at dotty.tools.dotc.transform.TreeMapWithStages.transform(TreeMapWithStages.scala:127)
	at dotty.tools.dotc.transform.ReifyQuotes$QuoteReifier.transform(ReifyQuotes.scala:409)
	at dotty.tools.dotc.transform.ReifyQuotes$$anon$1.transform(ReifyQuotes.scala:94)
	at dotty.tools.dotc.transform.MacroTransform.run(MacroTransform.scala:21)
	at dotty.tools.dotc.transform.ReifyQuotes.run(ReifyQuotes.scala:90)
	at dotty.tools.dotc.core.Phases$Phase.runOn$$anonfun$1(Phases.scala:316)
	at scala.collection.immutable.List.map(List.scala:286)
	at dotty.tools.dotc.core.Phases$Phase.runOn(Phases.scala:318)
	at dotty.tools.dotc.Run.runPhases$4$$anonfun$4(Run.scala:158)
	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.IndexedSeqOptimized.foreach(IndexedSeqOptimized.scala:36)
	at scala.collection.IndexedSeqOptimized.foreach$(IndexedSeqOptimized.scala:33)
	at scala.collection.mutable.ArrayOps$ofRef.foreach(ArrayOps.scala:198)
	at dotty.tools.dotc.Run.runPhases$5(Run.scala:170)
	at dotty.tools.dotc.Run.compileUnits$$anonfun$1(Run.scala:178)
	at dotty.runtime.function.JFunction0$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:185)
	at dotty.tools.dotc.Run.compileSources(Run.scala:120)
	at dotty.tools.dotc.Run.compile(Run.scala:104)
	at dotty.tools.dotc.Driver.doCompile(Driver.scala:35)
	at dotty.tools.dotc.Driver.process(Driver.scala:180)
	at dotty.tools.dotc.Driver.process(Driver.scala:149)
	at dotty.tools.dotc.Driver.process(Driver.scala:161)
	at dotty.tools.dotc.Driver.main(Driver.scala:188)
	at dotty.tools.dotc.Main.main(Main.scala)```
</details>