Empty block causes REPL to crash

[Glavo]

scala> {}                                                                                                                                                                              
Exception in thread "main" java.lang.AssertionError: assertion failed
	at dotty.DottyPredef$.assertFail(DottyPredef.scala:18)
	at dotty.tools.repl.ReplCompiler.createUnit(ReplCompiler.scala:143)
	at dotty.tools.repl.ReplCompiler.compile(ReplCompiler.scala:162)
	at dotty.tools.repl.ReplDriver.compile(ReplDriver.scala:216)
	at dotty.tools.repl.ReplDriver.interpret(ReplDriver.scala:182)
	at dotty.tools.repl.ReplDriver.loop$1(ReplDriver.scala:127)
	at dotty.tools.repl.ReplDriver.runUntilQuit$$anonfun$1(ReplDriver.scala:130)
	at dotty.tools.repl.ReplDriver.withRedirectedOutput$$anonfun$2$$anonfun$1(ReplDriver.scala:143)
	at scala.util.DynamicVariable.withValue(DynamicVariable.scala:62)
	at scala.Console$.withErr(Console.scala:196)
	at dotty.tools.repl.ReplDriver.withRedirectedOutput$$anonfun$1(ReplDriver.scala:143)
	at scala.util.DynamicVariable.withValue(DynamicVariable.scala:62)
	at scala.Console$.withOut(Console.scala:167)
	at dotty.tools.repl.ReplDriver.withRedirectedOutput(ReplDriver.scala:143)
	at dotty.tools.repl.ReplDriver.runUntilQuit(ReplDriver.scala:130)
	at dotty.tools.repl.Main$.main(Main.scala:6)
	at dotty.tools.repl.Main.main(Main.scala)