improve sql parser for informix skip/first clause.

src/main/java/com/alibaba/druid/sql/dialect/sqlserver/parser/SQLServerSelectParser.java

@@ -164,6 +164,8 @@ public class SQLServerSelectParser extends SQLSelectParser {
 
         parseGroupBy(queryBlock);
 
+        parseFetchClause(queryBlock);
+
         return queryRest(queryBlock);
     }
 

src/main/java/com/alibaba/druid/sql/dialect/sqlserver/visitor/SQLServerOutputVisitor.java

@@ -93,6 +93,8 @@ public class SQLServerOutputVisitor extends SQLASTOutputVisitor implements SQLSe
             x.getGroupBy().accept(this);
         }
 
+        printFetchFirst(x);
+
         return false;
     }