diplomacy: reprotect Node bundles after module construction is completed

src/main/scala/diplomacy/LazyModule.scala

@@ -165,7 +165,9 @@ sealed trait LazyModuleImpLike extends BaseModule
   protected[diplomacy] def instantiate() = {
     val childDangles = wrapper.children.reverse.flatMap { c =>
       implicit val sourceInfo = c.info
-      Module(c.module).dangles
+      val mod = Module(c.module)
+      mod.finishInstantiate()
+      mod.dangles
     }
     wrapper.instantiate()
     val nodeDangles = wrapper.nodes.reverse.flatMap(_.instantiate())
@@ -184,6 +186,10 @@ sealed trait LazyModuleImpLike extends BaseModule
     }
     (auto, dangles)
   }
+
+  protected[diplomacy] def finishInstantiate() {
+    wrapper.nodes.reverse.foreach { _.finishInstantiate() }
+  }
 }
 
 class LazyModuleImp(val wrapper: LazyModule) extends MultiIOModule with LazyModuleImpLike {

src/main/scala/diplomacy/Nodes.scala

@@ -93,6 +93,7 @@ abstract class BaseNode(implicit val valName: ValName)
   val serial = BaseNode.serial
   BaseNode.serial = BaseNode.serial + 1
   protected[diplomacy] def instantiate(): Seq[Dangle]
+  protected[diplomacy] def finishInstantiate(): Unit
 
   def name = lazyModule.name + "." + valName.name
   def omitGraphML = outputs.isEmpty && inputs.isEmpty
@@ -387,6 +388,10 @@ sealed abstract class MixedNode[DI, UI, EI, BI <: Data, DO, UO, EO, BO <: Data](
     danglesOut ++ danglesIn
   }
 
+  protected[diplomacy] def finishInstantiate() = {
+    bundlesSafeNow = false
+  }
+
   // connects the outward part of a node with the inward part of this node
   protected[diplomacy] def bind(h: OutwardNode[DI, UI, BI], binding: NodeBinding)(implicit p: Parameters, sourceInfo: SourceInfo) {
     val x = this // x := y