Fix leak of mmap'd memory

RealDataBench.cpp

@@ -54,6 +54,8 @@ int main(int argc, const char **argv) {
     const uint8_t *begin =
         (uint8_t *)mmap(0, size, PROT_READ, MAP_PRIVATE, fd, 0);
     madvise((void *)begin, size, MADV_SEQUENTIAL);
+    auto *const mapOriginal = begin;
+    const auto sizeOriginal = size;
 
     using StringView = std::basic_string_view<uint8_t>;
 
@@ -113,6 +115,7 @@ int main(int argc, const char **argv) {
         gcTime += now() - timer;
       }
     }
+    munmap((void *)mapOriginal, sizeOriginal);
     close(fd);
   }