+=for apidoc Am|void|OpMORESIB_set|OP *o|OP *sib
+Sets the sibling of C<o> to the non-zero value C<sib>. See also C<L</OpLASTSIB_set>>
+and C<L</OpMAYBESIB_set>>. For a higher-level interface, see
+C<L</op_sibling_splice>>.
+
+=for apidoc Am|void|OpLASTSIB_set|OP *o|OP *parent
+Marks C<o> as having no further siblings. On C<PERL_OP_PARENT> builds, marks
+o as having the specified parent. See also C<L</OpMORESIB_set>> and
+C<OpMAYBESIB_set>. For a higher-level interface, see
+C<L</op_sibling_splice>>.
+
+=for apidoc Am|void|OpMAYBESIB_set|OP *o|OP *sib|OP *parent
+Conditionally does C<OpMORESIB_set> or C<OpLASTSIB_set> depending on whether
+C<sib> is non-null. For a higher-level interface, see C<L</op_sibling_splice>>.