[llvm-objcopy] - Reimplement strip-dwo-groups.test to stop using the precompiled object.

When llvm-copy removes .dwo sections the index of symbol table,
the indices of the symbols and the indices of the sections which go
after the removed ones changes. That affects on SHT_GROUP sections,
which needs to be updated.

Initially this test used a precompiled object, I rewrote it to use YAML
and improved a bit.

Differential revision: https://reviews.llvm.org/D65273

llvm-svn: 367202