SI-9375 add synthetic readResolve only for static modules

For inner modules, the synthetic readResolve method would cause the
module constructor to be invoked on de-serialization in certain
situations. See the discussion in the ticket.

Adds a comprehensive test around serializing and de-serializing
modules.

1 files changed, 1 insertions, 2 deletions

diff --git a/test/files/run/idempotency-case-classes.check b/test/files/run/idempotency-case-classes.check
index 5a8d0ad9d3..ea698cec59 100644
--- a/test/files/run/idempotency-case-classes.check
+++ b/test/files/run/idempotency-case-classes.check
@@ -47,8 +47,7 @@ C(2,3)
     case <synthetic> def unapply(x$0: C): Option[(Int, Int)] = if (x$0.==(null))
       scala.this.None
     else
-      Some.apply[(Int, Int)](scala.Tuple2.apply[Int, Int](x$0.x, x$0.y));
-    <synthetic> private def readResolve(): Object = C
+      Some.apply[(Int, Int)](scala.Tuple2.apply[Int, Int](x$0.x, x$0.y))
   };
   Predef.println(C.apply(2, 3))
 }