Move Node::type to beginning of Node

This prepares us to have a variable size leaf type

ConflictSet.cpp

@@ -231,18 +231,18 @@ enum class Type : int8_t {
 constexpr static int kPartialKeyMaxLenEntryPresent = 24;
 
 struct Node {
+  Type type = Type::Invalid;
+
   /* begin section that's copied to the next node */
+  bool entryPresent = false;
+  uint8_t parentsIndex = 0;
+  int8_t partialKeyLen = 0;
+  int32_t numChildren = 0;
   Node *parent = nullptr;
   uint8_t partialKey[kPartialKeyMaxLenEntryPresent];
   // If not entryPresent, then the partial key might spill over into entry
   Entry entry;
-  int32_t numChildren = 0;
-  bool entryPresent = false;
-  uint8_t parentsIndex = 0;
-  int8_t partialKeyLen = 0;
   /* end section that's copied to the next node */
-
-  Type type = Type::Invalid;
 };
 
 static_assert(offsetof(Node, entry) ==
@@ -571,7 +571,9 @@ Node *&getOrCreateChild(Node *&self, uint8_t index,
     if (self->numChildren == 16) {
       auto *self16 = static_cast<Node16 *>(self);
       auto *newSelf = allocators->node48.allocate();
-      memcpy((void *)newSelf, self, offsetof(Node, type));
+      memcpy((char *)newSelf + sizeof(Node::type),
+             (char *)self + sizeof(Node::type),
+             sizeof(Node) - sizeof(Node::type));
       newSelf->nextFree = 16;
       int i = 0;
       for (auto x : self16->index) {
@@ -610,7 +612,9 @@ Node *&getOrCreateChild(Node *&self, uint8_t index,
     if (self->numChildren == 48) {
       auto *self48 = static_cast<Node48 *>(self);
       auto *newSelf = allocators->node256.allocate();
-      memcpy((void *)newSelf, self, offsetof(Node, type));
+      memcpy((char *)newSelf + sizeof(Node::type),
+             (char *)self + sizeof(Node::type),
+             sizeof(Node) - sizeof(Node::type));
       newSelf->bitSet = self48->bitSet;
       newSelf->bitSet.forEachInRange(
           [&](int i) {
@@ -1542,7 +1546,9 @@ template <bool kBegin>
 
         *self = allocators->node1.allocate();
 
-        memcpy((void *)*self, old, offsetof(Node, type));
+        memcpy((char *)*self + sizeof(Node::type),
+               (char *)old + sizeof(Node::type),
+               sizeof(Node) - sizeof(Node::type));
         (*self)->partialKeyLen = partialKeyIndex;
         (*self)->entryPresent = false;
         (*self)->numChildren = 0;