Revert r356738 "[llvm-objcopy] - Implement replaceSectionReferences for GroupSection class."

Seems this broke ubsan bot:
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap-ubsan/builds/11760

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356745 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed