Update perlfunc.pod smoothly linking the disjoint sentences

[jidanni]

https://www.google.com/search?q=is+also+a+conjunction . Or something like that.

[Grinnz]

It doesn't make much difference, but I don't think this is an improvement. The previous sentence indicates that it operates on @ARGV sometimes and @_ other times; this sentence lists other constructs where it will operate on @ARGV and not @_; so it is not an addition to the previous sentence, but an exception to the second half of it.

As an unrelated nitpick, the pop and shift sections should be kept corresponding.