How to find out the file through which an Apps standard package is created

Veera Boda pinged me today. He gave me this error which was coming during adconfig:

Cause: afpgdbcf failed due to ORA-04063: package body "APPS.FND_PROFILE" has errors
ORA-06508: PL/SQL: could not find program unit being called: "APPS.FND_PROFILE"
ORA-06512: at "APPS.FND_WEB_CONFIG", line 269
ORA-06512: at "APPS.FND_SECURITY_PKG", line 350

He said that he had followed Metalink Note 178001.1 to drop obsolete objects. On checking 178001.1, I found that it was related to 11.5.2 and advised running a script $FND_TOP/admin/sql/fnddold.sql which dropped obsolete objects. Apparently that script also dropped some objects like FND_PROFILE and FND_USER_PKG. Boda wanted to know how he could create those dropped objects. I thought of Electronic Technical Reference Manual available thru http://etrm.oracle.com which requires metalink login. However etrm has definitions of objects starting from 11.5.7. They don't have 11.5.2 objects. Then I thought of an easy way which I had discovered for fixing invalid objects. If you query a package's source code, you can find the line which has the version information. The version information line has the name of the file through which the package was created. For example:

select line,text from dba_source where object_name='FND_USER_PKG' and line < style="font-weight: bold;">/* $Header: AFSCUSRB.pls 115.150 2007/06/01 16:37:07 fskinner ship $ */
3
4
/* START PARTY */


From the above query I come to know that AFSCUSRB.pls file created the package body FND_USER_PKG. The naming convention of the files is like this:

If the file's primary name ends with an S then it creates the package specification.
If the file's primary name ends with a B then it creates the package body.

For example AFSCUSRS.pls creates package specification of FND_USER_PKG and AFSCUSRB.pls creates the package body.

After tracing the files which created the dropped packages, Boda was able to recreate all of them and restore normalcy to his instance.