parse.y:3154
static void
heredoc_restore(here)
    NODE *here;
{
    VALUE line = here->nd_orig;
    lex_lastline = line;
    lex_pbeg = RSTRING(line)->ptr;
    lex_pend = lex_pbeg + RSTRING(line)->len;
    lex_p = lex_pbeg + here->nd_nth;
    heredoc_end = ruby_sourceline;
    ruby_sourceline = nd_line(here);
    dispose_string(here->nd_lit);
    rb_gc_force_recycle((VALUE)here);
}
