Nested alias doesn't work

[waitingkuo]

from apache/datafusion#2867

while we have nested alias, the outer doesn't work

use sqlparser::dialect::GenericDialect;
use sqlparser::parser::Parser;

fn main() {

    let dialect = GenericDialect {}; // or AnsiDialect

    let sql = "SELECT __t404.__c394, __t404.__c395, __t404.__c396, __t404.__c397
                FROM ((
                    (SELECT test1.c0 AS __c394, test1.c1 AS __c395, test1.c2 AS __c396, test1.c3 AS __c397
                        FROM (test1)) __t398
                    INNER JOIN
                    (SELECT test1.c0 AS __c399, test1.c1 AS __c400, test1.c2 AS __c401, test1.c3 AS __c402
                        FROM (test1)) __t403
                    ON __t398.__c395 = __t403.__c401) __t404)
                WHERE __t404.__c395 != __t404.__c396; ";



    let ast = Parser::parse_sql(&dialect, sql).unwrap();

    println!("AST: {:?}", ast);
} 

➜  sp git:(master) ✗ cargo run
   Compiling sp v0.1.0 (/Users/willy/willy/df-workspace/sp)
    Finished dev [unoptimized + debuginfo] target(s) in 0.30s
     Running `target/debug/sp`
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: ParserError("Expected ), found: __t404")', src/main.rs:26:48
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

while this works

use sqlparser::dialect::GenericDialect;
use sqlparser::parser::Parser;
                        
fn main() {                                                              
      
    let dialect = GenericDialect {}; // or AnsiDialect

    /* 
    let sql = "SELECT a, b, 123, myfunc(b) \
               FROM table_1 \
               WHERE a > b AND b < 100 \
               ORDER BY a DESC, b";
               */
    let sql = "SELECT __c394, __c395, __c396, __c397
                FROM ((
                    (SELECT test1.c0 AS __c394, test1.c1 AS __c395, test1.c2 AS __c396, test1.c3 AS __c397
                        FROM (test1)) __t398
                    INNER JOIN
                    (SELECT test1.c0 AS __c399, test1.c1 AS __c400, test1.c2 AS __c401, test1.c3 AS __c402
                        FROM (test1)) __t403
                    ON __t398.__c395 = __t403.__c401) )
                WHERE __c395 != __c396; ";

    

    let ast = Parser::parse_sql(&dialect, sql).unwrap();

    println!("AST: {:?}", ast);
}