As discussed on llvm-dev I've implemented the first basic steps towards
llvm-objcopy/llvm-objtool (name pending).
This change adds the ability to copy (without modification) 64-bit
little endian ELF executables that have SHT_PROGBITS, SHT_NOBITS,
SHT_NULL and SHT_STRTAB sections.
Patch by Jake Ehrlich
Differential Revision: https://reviews.llvm.org/D33964
llvm-svn: 308559
Petr Hosek