Fix and reinstate repl/errmsgs

Author: dwijnand

compiler/src/dotty/tools/repl/ReplDriver.scala

@@ -1,6 +1,6 @@
 package dotty.tools.repl
 
-import java.io.{File => JFile, PrintStream, PrintWriter}
+import java.io.{BufferedWriter, File => JFile, OutputStreamWriter, PrintStream, PrintWriter}
 import java.nio.charset.StandardCharsets
 
 import dotty.tools.dotc.ast.Trees._
@@ -428,7 +428,7 @@ class ReplDriver(settings: Array[String],
   /** Like ConsoleReporter, but without file paths or real -Xprompt'ing */
   private object ReplConsoleReporter extends ConsoleReporter(
     reader = null, // this short-circuits the -Xprompt display from waiting for an input
-    writer = new PrintWriter(out, /* autoFlush = */ true), // write to out, not Console.err
+    writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(out, StandardCharsets.UTF_8)), /* autoFlush = */ true), // write to out, not Console.err
   ) {
     override def posFileStr(pos: SourcePosition) = "" // omit file paths
   }

compiler/test-resources/pending/repl/errmsgs renamed to compiler/test-resources/repl/errmsgs

@@ -51,19 +51,19 @@ scala> abstract class C { type T; val x: T; val s: Unit = { type T = String; var
 1 | abstract class C { type T; val x: T; val s: Unit = { type T = String; var y: T = x; locally { def f() = { type T = Int; val z: T = y }; f() } }; }
   |                                                                                  ^
   |Found:    (C.this.x : C.this.T)
-  |Required: T?
+  |Required: T²
   |
   |where:    T  is a type in class C
-  |          T? is a type in the initializer of value s which is an alias of String
+  |          T² is a type in the initializer of value s which is an alias of String
 longer explanation available when compiling with `-explain`
 -- [E007] Type Mismatch Error: -------------------------------------------------
 1 | abstract class C { type T; val x: T; val s: Unit = { type T = String; var y: T = x; locally { def f() = { type T = Int; val z: T = y }; f() } }; }
   |                                                                                                                                    ^
   |Found:    (y : T)
-  |Required: T?
+  |Required: T²
   |
   |where:    T  is a type in the initializer of value s which is an alias of String
-  |          T? is a type in method f which is an alias of Int
+  |          T² is a type in method f which is an alias of Int
 longer explanation available when compiling with `-explain`
 2 errors found
 scala> class Foo() { def bar: Int = 1 }; val foo = new Foo(); foo.barr