Missing position while compiling case classes from tasty

[nicolasstucki]

When compiling from tasty (tests in tests/posFromTasty/)

package foo
case class Foo()

When recompiling the code loaded from tasty there is position missing on the desugared apply method

java.lang.AssertionError: assertion failed: position not set for DefDef(apply,List(),List(List()),TypeTree[TypeRef(ThisType(TypeRef(NoPrefix,module class lang)),Object)],Apply(Select(This(Ident(Foo$)),apply),List())) # 10081
	at scala.Predef$.assert(Predef.scala:219)
	at dotty.tools.dotc.typer.Typer$.assertPositioned(Typer.scala:63)
	at dotty.tools.dotc.typer.Typer.$anonfun$typed$2(Typer.scala:1705)
	at dotty.tools.dotc.reporting.trace$.apply(trace.scala:23)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:1702)
	at dotty.tools.dotc.typer.Typer.traverse$1(Typer.scala:1728)
	at dotty.tools.dotc.typer.Typer.typedStats(Typer.scala:1751)
	at dotty.tools.dotc.transform.Erasure$Typer.typedStats(Erasure.scala:662)
	at dotty.tools.dotc.typer.Typer.$anonfun$typedClassDef$1(Typer.scala:1415)
...

[nicolasstucki]

This can be reproduced with

echo "package foo\ncase class Foo()\n" > Foo.scala
sbt "dotc Foo.scala"
sbt "dotc -tasty -classpath . foo.Foo"

[nicolasstucki]

#3771 showed that this is fixed. The regression test was not added as this was a minimization of code found all over tests/pos.