Add test

Should have been added on final vals commit.

Author: odersky

tests/run/singletons.check

@@ -0,0 +1,3 @@
+a
+g
+g

tests/run/singletons.scala

@@ -0,0 +1,71 @@
+
+object Test {
+
+  val x: 1 = 1
+  final val y = x
+  val z: 1 = y
+
+  object O { final val x = 42 }
+  val fourtyTwo: 42 = O.x
+
+  final val a = { println("a"); 2 } // side effect does not matter for type but needs to be preserved at runtime
+  val b: 2 = a
+
+  def f: 3 = 3
+  final val c = f
+
+  final def g: 4 = { println("g"); 4 } // side effect does not matter for type but needs to be preserved at runtime
+  final val gv1: 4 = g
+  final val gv2: 4 = g
+
+  val dc: 3.0 = 3.0
+  final val dc1 = dc
+  val fc: 3.0f = 3.0f
+  final val fc1 = fc
+
+  val t: true = true
+
+  val str: "" = ""
+  final val str2 = str
+
+  def main(args: Array[String]) = {
+  }
+}
+/* To do: test that after erasure we have generated code like this:
+ *
+package <empty> {
+  final lazy module val Test: Test$ = new Test$()
+  final module class Test$() extends Object() { this: <notype> =>
+    <accessor> def x(): Int = 1
+    final <accessor> def y(): Int = 1
+    <accessor> def z(): Int = 1
+    final lazy module val O: Test.O$ = new Test.O$()
+    final module class O$() extends Object() { this: <notype> =>
+      final <accessor> def x(): Int = 42
+    }
+    <accessor> def fourtyTwo(): Int = 42
+    final <accessor> def a(): Int = {
+      println("a")
+      2
+    }
+    <accessor> def b(): Int = 2
+    def f(): Int = 3
+    final <accessor> def c(): Int = Test.f()
+    final def g(): Int = {
+      println("g")
+      4
+    }
+    final <accessor> def gv(): Int = Test.g()
+    <accessor> def dc(): Double = 3.0
+    final <accessor> def dc1(): Double = 3.0
+    <accessor> def fc(): Float = 3.0
+    final <accessor> def fc1(): Float = 3.0
+    <accessor> def t(): Boolean = true
+    <accessor> def str(): String = ""
+    final <accessor> def str2(): String = ""
+    def main(args: String[]): Unit = {
+      ()
+    }
+  }
+}
+*/