Need definition for 'construct' (noun) for use in documentation

[jkeenan]

As part of my research on Fatalization of currently deprecated goto construct I have been re-reading our current documentation of goto in blead and have been trying to locate in our test suite examples of each claim made in that documentation. What we find -- or fail to find -- there will have an impact on the documentation updates provided as part of a pull request like the current https://github.com/Perl/perl5/pull/23782. I've posted the preliminary results of that documentation review here.

This is the sixth in a series of GH issues addressing the items which I believe are lacking in that documentation.

perldoc -f goto states:

Use of "goto LABEL" or "goto EXPR" to jump into a construct is
deprecated and will issue a warning; it will become a fatal
error in Perl 5.42. While still available, it may not be used to
go into any construct that requires initialization, such as a
subroutine, a "foreach" loop, or a "given" block. 

"[C]onstruct" (as a noun) is a vague term for which we have no definition -- but we use it a lot:

$ ack -i '\bconstruct\b' pod | ack -v delta

Discuss whether we should have a definition and what it should be.