Fix for bug 1446043 SPJ's can contain duplicate column names coming from different tables which will be resolved later by renaming the columns. so there is no need to check for duplicates at the beginning of bind node for SPJ's.
LP 1444044, dup col definitions are not detected During a create table or create view, duplicate col names are not being detected and an error is not being returned. This results in an incorect table or view being created. An error may or may not be returned later depending on how that object is being used.
That has been fixed to detect dup cols and return an error message during create time.
Fixing it now so users dont create incorrect objects by mistake.