goto jumping into binary or list operators

[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
#23782. I've posted the preliminary results
of that documentation review
here.

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

perldoc -f goto states:

In general, ['goto EXPR' or 'goto LABEL']
may not be used to jump into the parameter of a binary or list
operator, but it may be used to jump into the *first* parameter
of a binary operator.  (The "=" assignment operator's "first"
operand is its right-hand operand.) 

Does this mean that goto LABEL could be used to jump into the second
parameter of a binary operator?

Do we currently have any tests that illustrate use of goto with either
binary or list operators?

[jkeenan]

As reported by @trwyant in #23618 (comment), at least one aspect of this ticket's ask is covered:

# [perl #132854]
# Goto the *first* parameter of a binary expression, which is harmless.
eval {
    goto __GEN_2;
    my $sent = do {
        __GEN_2:
    };
};
is $@,'', 'goto the first parameter of a binary expression [perl #132854]';

[tonycoz]

t/lib/croak/pp_ctl tests failing to jump into a binary or list expression