depth can be negative (qsearch)

Author: Exclusivefrog28

src/TranspositionTable.cpp

@@ -40,7 +40,7 @@ void TranspositionTable::setEntry(const ChessBoard &board, const Move bestMove,
 
     const NodeType savedType = entries[index].nodeType;
 
-    const Entry entry = {board.hashCode, bestMove, score, static_cast<uint8_t>(depth), nodeType};
+    const Entry entry = {board.hashCode, bestMove, score, static_cast<int8_t>(depth), nodeType};
 
     //REPLACEMENT SCHEME
     // 1. Prefer EXACT nodes to bounds

src/TranspositionTable.h

@@ -23,7 +23,7 @@ class TranspositionTable {
         uint64_t key: 64;
         Move bestMove;
         int32_t score: 32;
-        uint8_t depth: 8;
+        int8_t depth: 8;
         NodeType nodeType: 3;
     };