Remove performance-only code from debug build for increased coverage

ConflictSet.cpp

@@ -2431,9 +2431,14 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
       return;
     }
     this->oldestVersion = oldestVersion;
+#ifdef NDEBUG
+    // This is here for performance reasons, since we want to amortize the cost
+    // of storing the search path as a string. In tests, we want to exercise the
+    // rest of the code often.
     if (keyUpdates < 100) {
       return;
     }
+#endif
     Node *n = firstGeq(root, removalKey).n;
     // There's no way to erase removalKey without introducing a key after it
     assert(n != nullptr);
@@ -2461,9 +2466,6 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
       removalKey = {};
       return;
     }
-    if (keyUpdates == 0) {
-      keyUpdates = 10;
-    }
     removalKeyArena = Arena();
     removalKey = getSearchPath(removalKeyArena, n);
   }
@@ -2504,7 +2506,7 @@ int64_t &maxVersion(Node *n, ConflictSet::Impl *impl) {
     return impl->rootMaxVersion;
   }
   switch (n->getType()) {
-  case Type_Node0:
+  case Type_Node0:           // GCOVR_EXCL_LINE
     __builtin_unreachable(); // GCOVR_EXCL_LINE
   case Type_Node3: {
     auto *n3 = static_cast<Node3 *>(n);