SI-6863 root cause fixed using factory of scala.runtime.*Ref

This commit does away with an error-prone division of labor between
UnCurry and LambdaLift, a division of labor by which UnCurry had to
anticipate under which circumstances LambdaLift creates a
scala.runtime.*Ref whose initial value is given by a an expression
including a Try in non-statement position. That sounds complicated,
and it is.

The solution so far (fixing SI-6863) is replaced by a simpler approach,
at the cost of forward binary comptability with pre-2.11 releases,
this time fixing the root cause of SI-6863.

From now on, a s.r.*Ref is instantiated via invocation of
a static factory method in the s.r.*Ref class in question.
Unlike the code that was emitted so far (which involved
NEW refclass, DUP, expr, INVOKESPECIAL refclass.<init>)
the "expr" doesn't appear on the operand stack on top
of the *Ref value being initialized. In other words,
the *Ref initialization is in statement position provided "expr" is.

1 files changed, 2 insertions, 2 deletions

diff --git a/test/files/run/t6028.check b/test/files/run/t6028.check
index 2ec639fce2..57fd58f7d3 100644
--- a/test/files/run/t6028.check
+++ b/test/files/run/t6028.check
@@ -15,11 +15,11 @@ package <empty> {
       }
     };
     def bar(barParam: Int): Object = {
-      @volatile var MethodLocalObject$module: runtime.VolatileObjectRef = new runtime.VolatileObjectRef(null);
+      @volatile var MethodLocalObject$module: runtime.VolatileObjectRef = scala.runtime.VolatileObjectRef.zero();
       T.this.MethodLocalObject$1(barParam, MethodLocalObject$module)
     };
     def tryy(tryyParam: Int): Function0 = {
-      var tryyLocal: runtime.IntRef = new runtime.IntRef(0);
+      var tryyLocal: runtime.IntRef = scala.runtime.IntRef.create(0);
       {
         (new anonymous class $anonfun$tryy$1(T.this, tryyParam, tryyLocal): Function0)
       }