is a pointer to the C function that is to be added to that opcode's
check chain, and C<old_checker_p> points to the storage location where a
pointer to the next function in the chain will be stored. The value of
-C<new_pointer> is written into the L</PL_check> array, while the value
+C<new_checker> is written into the L</PL_check> array, while the value
previously stored there is written to C<*old_checker_p>.
L</PL_check> is global to an entire process, and a module wishing to