Notationally distinct is not terribly important. A number of your "different" ways are extremely minor variations. For example, 3 and 4 differ only in terms of the variable used and whether the condition is placed before or after the block; they not only do exactly the same thing, they do it in exactly the same way. Counting them as different is pedantic in the extreme; if you really think that's clever, I can easily think of a couple hundred ways to do it in line number BASIC.

More, some of your ways to do it are simply taking more general mechanisms and applying them to a problem normally solved with a more specific type of construct. For example, using a while loop with a counter at the end of it that is not used for anything else other than to count out the iterations of the loop is something you can do in any language that has while loops, because the for loop is conceptually a special case of the while loop. Congratulations, you discovered a general principle that applies to all languages.

Perl does have a few more than other languages, but it's not quite like you make out. Further, I'd say that these extras (like map) are not "extra" per se but are part of what makes a rich language such as Perl rich. I use Emacs lisp, and it too has some of these higher-level constructs that are essentially a specialised case of something that with a bit more work on the programmer's part could be done with standard flow control mechanisms, but the higher-level features, where appropriate, are less work to use. (And speaking of lisp, does anyone else wish Perl had an equivalent for rassq? Or does it, and I'm missing it for lack of knowing where to look?)