update go-sqlite3 to v0.18.0 (#3204)

vendor/github.com/ncruces/go-sqlite3/txn.go

@@ -32,6 +32,19 @@ func (c *Conn) Begin() Txn {
 	return Txn{c}
 }
 
+// BeginConcurrent starts a concurrent transaction.
+//
+// Experimental: requires a custom build of SQLite.
+//
+// https://sqlite.org/cgi/src/doc/begin-concurrent/doc/begin_concurrent.md
+func (c *Conn) BeginConcurrent() (Txn, error) {
+	err := c.Exec(`BEGIN CONCURRENT`)
+	if err != nil {
+		return Txn{}, err
+	}
+	return Txn{c}, nil
+}
+
 // BeginImmediate starts an immediate transaction.
 //
 // https://sqlite.org/lang_transaction.html
@@ -217,7 +230,7 @@ func (c *Conn) txnExecInterrupted(sql string) error {
 	return err
 }
 
-// TxnState starts a deferred transaction.
+// TxnState determines the transaction state of a database.
 //
 // https://sqlite.org/c3ref/txn_state.html
 func (c *Conn) TxnState(schema string) TxnState {
@@ -292,3 +305,11 @@ func updateCallback(ctx context.Context, mod api.Module, pDB uint32, action Auth
 		c.update(action, schema, table, int64(rowid))
 	}
 }
+
+// CacheFlush flushes caches to disk mid-transaction.
+//
+// https://sqlite.org/c3ref/db_cacheflush.html
+func (c *Conn) CacheFlush() error {
+	r := c.call("sqlite3_db_cacheflush", uint64(c.handle))
+	return c.error(r)
+}