add mysql deallocate prepare statement parse

src/test/java/com/alibaba/druid/sql/parser/DeallocatePrepareTest.java

@@ -0,0 +1,23 @@
+package com.alibaba.druid.sql.parser;
+
+import org.junit.Assert;
+
+import com.alibaba.druid.sql.ast.SQLStatement;
+import com.alibaba.druid.sql.dialect.mysql.ast.statement.MysqlDeallocatePrepareStatement;
+import com.alibaba.druid.sql.dialect.mysql.parser.MySqlStatementParser;
+
+import junit.framework.TestCase;
+
+public class DeallocatePrepareTest extends TestCase {
+
+	public void test() {
+		String sql = "DEALLOCATE PREPARE stmt1";
+		MySqlStatementParser parser = new MySqlStatementParser(sql);
+		SQLStatement stmt =parser.parseStatement();
+		Assert.assertEquals(MysqlDeallocatePrepareStatement.class, stmt.getClass());
+		MysqlDeallocatePrepareStatement dpStmt = (MysqlDeallocatePrepareStatement) stmt;
+		Assert.assertEquals("stmt1", dpStmt.getStatementName().getSimpleName());
+		Assert.assertEquals(sql, dpStmt.toString());
+	}
+	
+}