Specialization should not duplicate tailrec-annotated methods + backend issue

[scabug]

sun@sun-cpu:~/workspace/dev/miniboxing-plugin/sandbox(wip)$ scalac -version
Scala compiler version 2.11.5-20141107-114204-b1e6f57b2b -- Copyright 2002-2013, LAMP/EPFL

sun@sun-cpu:~/workspace/dev/miniboxing-plugin/sandbox(wip)$ scala -version
Scala code runner version 2.11.5-20141107-114204-b1e6f57b2b -- Copyright 2002-2013, LAMP/EPFL

sun@sun-cpu:~/workspace/dev/miniboxing-plugin/sandbox(wip)$ cat gh-bug-181-spec.scala 
package miniboxing.tests.bug181.spec_crash
import annotation.tailrec

class ConsList[@specialized(Int) A](head: A, tail: ConsList[A]) {
  @tailrec final def print(a: A): Unit = {
    print(head)
    if (tail != null) {
      print(", ")
      tail.print(a)
    }
  }
}

object Test {
  def main(args: Array[String]): Unit = {

    def makeEnd[T](t: T) = new ConsList[T](t, null)

    val intList = new ConsList(1,
                    new ConsList(2,
                      new ConsList(3, 
                        makeEnd(4)
                      )
                    )
                  )

    // expected output: 1, 2, 3, 4
    // actual output: 1, 2, 3, 0
    intList.print(4)
  }
}

sun@sun-cpu:~/workspace/dev/miniboxing-plugin/sandbox(wip)$ scalac gh-bug-181-spec.scala 

sun@sun-cpu:~/workspace/dev/miniboxing-plugin/sandbox(wip)$ scala miniboxing.tests.bug181.spec_crash.Test
java.lang.VerifyError: Bad type on operand stack
Exception Details:
  Location:
    miniboxing/tests/bug181/spec_crash/ConsList$mcI$sp.print$mcI$sp(I)V @4: getfield
  Reason:
    Type 'miniboxing/tests/bug181/spec_crash/ConsList' (current frame, stack[1]) is not assignable to 'miniboxing/tests/bug181/spec_crash/ConsList$mcI$sp'
  Current Frame:
    bci: @4
    flags: { }
    locals: { 'miniboxing/tests/bug181/spec_crash/ConsList', integer }
    stack: { 'scala/Predef$', 'miniboxing/tests/bug181/spec_crash/ConsList' }
  Bytecode:
    0000000: b200 182a b400 1ab8 0020 b600 242a b400
    0000010: 26c7 0008 b200 2c57 b1b2 0018 122e b600
    0000020: 242a b400 261b 3c4b a7ff d8            
  Stackmap Table:
    full_frame(@0,{Object[#5],Integer},{})
    same_frame(@25)

    at miniboxing.tests.bug181.spec_crash.Test$.main(gh-bug-181-spec.scala:19)
    at miniboxing.tests.bug181.spec_crash.Test.main(gh-bug-181-spec.scala)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at scala.reflect.internal.util.ScalaClassLoader$$anonfun$run$1.apply(ScalaClassLoader.scala:70)
    at scala.reflect.internal.util.ScalaClassLoader$class.asContext(ScalaClassLoader.scala:31)
    at scala.reflect.internal.util.ScalaClassLoader$URLClassLoader.asContext(ScalaClassLoader.scala:101)
    at scala.reflect.internal.util.ScalaClassLoader$class.run(ScalaClassLoader.scala:70)
    at scala.reflect.internal.util.ScalaClassLoader$URLClassLoader.run(ScalaClassLoader.scala:101)
    at scala.tools.nsc.CommonRunner$class.run(ObjectRunner.scala:22)
    at scala.tools.nsc.ObjectRunner$.run(ObjectRunner.scala:39)
    at scala.tools.nsc.CommonRunner$class.runAndCatch(ObjectRunner.scala:29)
    at scala.tools.nsc.ObjectRunner$.runAndCatch(ObjectRunner.scala:39)
    at scala.tools.nsc.MainGenericRunner.runTarget$1(MainGenericRunner.scala:65)
    at scala.tools.nsc.MainGenericRunner.run$1(MainGenericRunner.scala:87)
    at scala.tools.nsc.MainGenericRunner.process(MainGenericRunner.scala:98)
    at scala.tools.nsc.MainGenericRunner$.main(MainGenericRunner.scala:103)
    at scala.tools.nsc.MainGenericRunner.main(MainGenericRunner.scala)

Found while debugging https://github.com/miniboxing/miniboxing-plugin/issues/181.

[scabug]

Imported From: https://issues.scala-lang.org/browse/SI-9180?orig=1 Reporter: @VladUreche

[scabug]

@VladUreche said: Well, seems I killed two birds with one stone. The test case was meant to print:

1, 2, 3, 0

instead of

1, 2, 3, 4

But it turns out there's a VerifyError lurking in there as well, which doesn't show up when the class is generic.