Update REPL tests to the new extensions

Author: anatoliykmetyuk

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

@@ -170,8 +170,8 @@ class ReplCompilerTests extends ReplTest {
       run("""
         |trait Ord[T] {
         |  def compare(x: T, y: T): Int
-        |  def (x: T) < (y: T) = compare(x, y) < 0
-        |  def (x: T) > (y: T) = compare(x, y) > 0
+        |  extension (x: T) def < (y: T) = compare(x, y) < 0
+        |  extension (x: T) def > (y: T) = compare(x, y) > 0
         |}
         |
         |given IntOrd as Ord[Int] {