[Searchers] Remove weight from es, add nurs_depth

Having both weight and depth in execution state is wasteful,
therefore this patch removes weight.

The nurs:depth searcher is replaced by nurs:rp, which uses pow to compute
the weight

A new nurs:depth searcher is introduced that biases the search with depth,
making it the only other searcher that prefers to go deep (similar to dfs).

1 files changed, 0 insertions, 4 deletions

diff --git a/include/klee/ExecutionState.h b/include/klee/ExecutionState.h
index 891e6f06..95808be1 100644
--- a/include/klee/ExecutionState.h
+++ b/include/klee/ExecutionState.h
@@ -102,10 +102,6 @@ public:
   /// @brief Costs for all queries issued for this state, in seconds
   mutable time::Span queryCost;
 
-  /// @brief Weight assigned for importance of this state.  Can be
-  /// used for searchers to decide what paths to explore
-  double weight;
-
   /// @brief Exploration depth, i.e., number of times KLEE branched for this state
   unsigned depth;