Amortize cost of searching for continueKey

Bench.cpp

@@ -8,7 +8,7 @@ void monotonicallyIncreasing() {
   ankerl::nanobench::Bench bench;
   Facade facade{kWindow + 1};
 
-  bench.minEpochIterations(kWindow * 10);
+  bench.minEpochIterations(kWindow * 20);
 
   bench.warmup(kWindow).run("monotonically increasing", [&] {
     const int64_t remove = __builtin_bswap64(facade.getVersion() - kWindow);
@@ -106,4 +106,4 @@ void bulkFirstGeq() {
 int main() {
   monotonicallyIncreasing();
   bulkFirstGeq();
-}
+}