Override line and column in NoSourcePosition

Otherwise, usage causes an assertion error.

The use of the value -1 is in agreement with the documentation in
interfaces/src/dotty/tools/dotc/interfaces/SourcePosition.java

The REPL driver depends on these methods for ordering its output, and
some diagnostics are reported (intentionally) using NoSoucePosition.

Author: griggt

compiler/src/dotty/tools/dotc/util/SourcePosition.scala

@@ -86,6 +86,8 @@ extends SrcPos, interfaces.SourcePosition, Showable {
 
 /** A sentinel for a non-existing source position */
 @sharable object NoSourcePosition extends SourcePosition(NoSource, NoSpan, null) {
+  override def line: Int = -1
+  override def column: Int = -1
   override def toString: String = "?"
   override def withOuter(outer: SourcePosition): SourcePosition = outer
 }

compiler/test/dotty/tools/repl/ReplCompilerTests.scala

@@ -233,3 +233,31 @@ object ReplCompilerTests {
   }
 
 }
+
+class ReplXPrintTyperTests extends ReplTest(ReplTest.defaultOptions :+ "-Xprint:typer") {
+  @Test def i9111 = fromInitialState { implicit state =>
+    run("""|enum E {
+           |  case A
+           |}""".stripMargin)
+    assert(storedOutput().trim().endsWith("// defined class E"))
+  }
+
+  @Test def i10883 = fromInitialState { implicit state =>
+    run("val a = 42")
+    assert(storedOutput().trim().endsWith("val a: Int = 42"))
+  }
+}
+
+class ReplVerboseTests extends ReplTest(ReplTest.defaultOptions :+ "-verbose") {
+  @Test def i9111 = fromInitialState { implicit state =>
+    run("""|enum E {
+           |  case A
+           |}""".stripMargin)
+    assert(storedOutput().trim().endsWith("// defined class E"))
+  }
+
+  @Test def i10883 = fromInitialState { implicit state =>
+    run("val a = 42")
+    assert(storedOutput().trim().endsWith("val a: Int = 42"))
+  }
+}