blockchain: skip checking tx semantics in embedded block hash range

If the txes are bad, this'll be picked up by the block hash mismatch
since the tx merkle root is part of the block hash.

src/cryptonote_core/blockchain.cpp

@@ -4154,6 +4154,15 @@ void Blockchain::load_compiled_in_block_hashes()
 }
 #endif
 
+bool Blockchain::is_within_compiled_block_hash_area(uint64_t height) const
+{
+#if defined(PER_BLOCK_CHECKPOINT)
+  return height < m_blocks_hash_check.size();
+#else
+  return false;
+#endif
+}
+
 void Blockchain::lock()
 {
   m_blockchain_lock.lock();