[fix](syntax) multi statements must delim with semicolon

fe/fe-core/src/main/antlr4/org/apache/doris/nereids/DorisParser.g4

@@ -26,7 +26,7 @@ options { tokenVocab = DorisLexer; }
 }
 
 multiStatements
-    : (statement SEMICOLON*)+ EOF
+    : statement (SEMICOLON+ statement)* SEMICOLON* EOF
     ;
 
 singleStatement

fe/fe-core/src/test/java/org/apache/doris/nereids/parser/NereidsParserTest.java

@@ -55,11 +55,18 @@ public class NereidsParserTest extends ParserTestBase {
     @Test
     public void testParseMultiple() {
         NereidsParser nereidsParser = new NereidsParser();
-        String sql = "SELECT b FROM test;SELECT a FROM test;";
+        String sql = "SELECT b FROM test;;;;SELECT a FROM test;";
         List<Pair<LogicalPlan, StatementContext>> logicalPlanList = nereidsParser.parseMultiple(sql);
         Assertions.assertEquals(2, logicalPlanList.size());
     }
 
+    @Test
+    public void testParseMultipleError() {
+        NereidsParser nereidsParser = new NereidsParser();
+        String sql = "SELECT b FROM test SELECT a FROM test;";
+        Assertions.assertThrowsExactly(ParseException.class, () -> nereidsParser.parseMultiple(sql));
+    }
+
     @Test
     public void testSingle() {
         NereidsParser nereidsParser = new NereidsParser();

regression-test/suites/insert_p0/insert.groovy

@@ -102,7 +102,7 @@ suite("insert") {
           partition p2 values[('50'), ('100'))
         )
         distributed by hash(id) buckets 100
-        properties('replication_num'='1')
+        properties('replication_num'='1');
 
         insert into table_test_insert1 values(1), (50);