When Did a Module Become Core?

[James Keenan]

What is the simplest way to determine for a given CPAN module (a) 
whether it is part of the Perl core; (b) when it became part of the 
core (i.e., which version of Perl); and (c) which version is considered 
core?

Reason for question:  As part of Phalanx project, am doing revisions to 
the test suite of a popular but non-core Perl module.  I wish to 
upgrade the module's test suite to use Test::More's functionality and 
to create temporary files safely with File::Temp.  I need to determine 
whether or not it is advisable to include these module's in the 
Makefile.PL and, if so, what versions.

Thanks in advance.
Jim Keenan