Make i23882 test output stable

Sort declared methods by name, since their original order can vary.

Author: odersky

tests/run/i23882.check

@@ -1,6 +1,6 @@
-public void Foo.foo(java.lang.Object)
-public void Foo.foo(scala.Equals)
 public void Foo.bar(Bar)
 public void Foo.bar2(Bar)
 public void Foo.bar3(Bar)
 public void Foo.bar4(Bar)
+public void Foo.foo(java.lang.Object)
+public void Foo.foo(scala.Equals)

tests/run/i23882.scala

@@ -2,6 +2,7 @@
 
 import scala.collection.*
 import scala.caps.Pure
+import java.util.Arrays
 
 trait Bar
 
@@ -14,5 +15,5 @@ class Foo:
   def bar4[T <: Pure](x: T & Bar): Unit = ???      // erases to Bar
 
 @main def Test =
-  for mtd <- classOf[Foo].getDeclaredMethods do
+  for mtd <- classOf[Foo].getDeclaredMethods.sortBy(_.toString) do
     println(mtd)