instead of NetBSD's own elf.h. See: http://mail-index.netbsd.org/tech-toolchain/2010/08/20/msg001355.html
changes: -portability/build system improvements (Windows/QNX) -API extensions -minor bugfixes -improved builtin sanity checks
provided by Andrey Petrov in PR 24658 Libelf - ELF object file access library.