Fix compilation on Win after r5867.

src/profile-generator-inl.h

Index: src/profile-generator-inl.h
diff --git a/src/profile-generator-inl.h b/src/profile-generator-inl.h
index 71de2d1797be03e2b20354aaa40724f4cfac4410..c8c98cc7847adbecce2ee84288a85b6ef137ebc2 100644
--- a/src/profile-generator-inl.h
+++ b/src/profile-generator-inl.h
@@ -122,6 +122,11 @@ CodeEntry* ProfileGenerator::EntryForVMState(StateTag tag) {
 }
 
 
+inline uint64_t HeapEntry::id() {
+  return *(reinterpret_cast<uint64_t*>(&id_));
+}
+
+
 template<class Visitor>
 void HeapEntriesMap::UpdateEntries(Visitor* visitor) {
   for (HashMap::Entry* p = entries_.Start();