treewide: avoid `goto &NAME' for tail recursion

treewide: avoid `goto &NAME' for tail recursion

While Perl implements tail recursion via `goto' which allows
avoiding warnings on deep recursion.  It doesn't (as of 5.28)
optimize the speed of such dispatches, though it may reduce
ephemeral memory usage.

Make the code less alien to hackers coming from other languages
by using normal subroutine dispatch.  It's actually slightly
faster in micro benchmarks due to the complexity of `goto &NAME'.