debug: temporarily leave preexec in place

src/main/scala/uncore/devices/debug/abstract_commands.scala

@@ -28,7 +28,8 @@ class ACCESS_REGISTERFields extends Bundle {
   */
   val size = UInt(3.W)
 
-  val reserved1 = UInt(1.W)
+  // HACK -- for now I have not yet deleted preexecval reserved1 = UInt(1.W)
+  val preexec = Bool()
 
   /* When 1, execute the program in the Program Buffer exactly once
             after performing the transfer, if any.