Use od instead of hexdump.
Use od instead of hexdump.

od is defined by POSIX and exists since version 1 AT&T Unix.
hexdump is not part of any standard as far as I know.
So od is a better choice than hexdump.

Differential Revision: https://reviews.llvm.org/D24205

git-svn-id: f6089bf0e6284f307027cef4f64114ee9ebb0424@280536 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/lld,llvm-mirror/lld