fix: parser no longer breaks on encountering indexes that contain expression columns

sample_data/test_schemas/food.sql

@@ -43,6 +43,7 @@ create table foods (rowid integer primary key,
     cook_ratio real not null default 1
 ) strict;
 create index foods_protein on foods(protein);
+create index foods_fake_index on foods(protein + 1);
 
 
 create table units (rowid integer primary key,