[llvm-objcopy] - Implement replaceSectionReferences for GroupSection class.

Currently, llvm-objcopy incorrectly handles compression and decompression of the
sections from COMDAT groups, because we do not implement the
replaceSectionReferences for this type of the sections.

The patch does that.

Differential revision: https://reviews.llvm.org/D59638

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356738 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed