Linux fixes + bug fix in bitset size calculation

VersionedMap.cpp

@@ -3,6 +3,8 @@
 #include <assert.h>
 #include <atomic>
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 #include <sys/mman.h>
 #include <sys/types.h>
 #include <unistd.h>
@@ -127,7 +129,7 @@ constexpr uint32_t kUpsizeNodes = kUpsizeBytes / sizeof(Node);
 static_assert(kUpsizeNodes * sizeof(Node) == kUpsizeBytes);
 
 struct BitSet {
-  explicit BitSet(uint32_t size) : words((uint64_t *)malloc(size / 64 + 64)) {}
+  explicit BitSet(uint32_t size) : words((uint64_t *)malloc(size / 8 + 8)) {}
 
   bool test(uint32_t i) const {
     return words[i >> 6] & (uint64_t(1) << (i & 63));
@@ -393,6 +395,7 @@ struct VersionedMap::Impl {
 
   template <std::memory_order kOrder>
   uint32_t child(uint32_t node, bool which, int64_t at) {
+	  static_assert(kOrder == std::memory_order_acquire || kOrder == std::memory_order_relaxed);
     auto &n = mm.base[node];
     if (n.updated.load(kOrder) && n.updateVersion <= at &&
         which == n.replacedPointer) {
@@ -576,4 +579,4 @@ int main() {
     });
   }
 }
-#endif
+#endif