I came across the ACME::Don't module.
It is used exactly like the do BLOCK function except that, instead of executing the block it controls, it...well...doesn't. It seems to me that you can use this to comment-out parts of code. When debugging, I sometimes knock out parts until the problem goes away.
I realize it's not as general as lexer comments, but still, it's interesting.
In reply to At last, block comments in Perl 5.6 ! by John M. Dlugosz
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