Remove a test print.
Don't dump 16-bit iret sections on x86_64

A kernel commit named:
  x86-64, espfix: Don't leak bits 31:16 of %esp returning to 16-bit stack

added a boatload of little sections that have no value for a coredump.

So ignore that section of memory.
Add basic section handle and support for phnum > 65534

Add the ability to handle sections, and if the number of phdrs is
more than 65534, use a NULL section to hold the phnum in the sh_info
field, per the specification.