Recommit r257912

Added forgotten ELFDumper.cpp to commit.

Initial commit message:
[llvm-readobj] Add support for TLSDESC_PLT and TLSDESC_GOT dynamic section tags to the llvm-readobj.

If module uses uses lazy TLSDESC relocations it should define DT_TLSDESC_PLT and DT_TLSDESC_GOT entries.
They were unknown for llvm-readobj before this patch.

Differential revision: http://reviews.llvm.org/D16224

llvm-svn: 257914