tests: Bring tool args reading to REPL tests

And, by doing so, reinstate the repl/i13208 script.

Author: dwijnand

compiler/test-resources/pending/repl/i13208.scala renamed to compiler/test-resources/repl/i13208.scala

@@ -1,11 +1,13 @@
 // scalac: -source:future -deprecation
 scala> type M[X] = X match { case Int => String case _ => Int }
--- Deprecation Warning:
+1 warning found
+-- Deprecation Warning: --------------------------------------------------------
 1 | type M[X] = X match { case Int => String case _ => Int }
   |                                               ^
   |        `_` is deprecated for wildcard arguments of types: use `?` instead
 scala> type N[X] = X match { case List[_] => Int }
--- Deprecation Warning:
+1 warning found
+-- Deprecation Warning: --------------------------------------------------------
 1 | type N[X] = X match { case List[_] => Int }
   |                                 ^
   |        `_` is deprecated for wildcard arguments of types: use `?` instead

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

@@ -64,19 +64,21 @@ extends ReplDriver(options, new PrintStream(out, true, StandardCharsets.UTF_8.na
 
     val expectedOutput = lines.flatMap(filterEmpties)
     val actualOutput = {
-      resetToInitial()
+      val opts = toolArgsParse(lines.take(1))
+      val (optsLine, inputLines) = if opts.isEmpty then ("", lines) else (lines.head, lines.drop(1))
+      resetToInitial(opts)
 
-      assert(lines.head.startsWith(prompt),
+      assert(inputLines.head.startsWith(prompt),
         s"""Each script must start with the prompt: "$prompt"""")
-      val inputRes = lines.filter(_.startsWith(prompt))
+      val inputRes = inputLines.filter(_.startsWith(prompt))
 
       val buf = new ArrayBuffer[String]
       inputRes.foldLeft(initialState) { (state, input) =>
         val (out, nstate) = evaluate(state, input)
         out.linesIterator.foreach(buf.append)
         nstate
       }
-      buf.toList.flatMap(filterEmpties)
+      (optsLine :: buf.toList).flatMap(filterEmpties)
     }
 
     if !FileDiff.matches(actualOutput, expectedOutput) then