[llvm-objdump] Add RAII for xar apis

Summary:
xar_open and xar_iter_new require manual calls to close/free functions
to deallocate resources. This makes it easy to introduce memory leaks,
so add RAII struct wrappers for these resources.

Reviewers: enderby, rafael, compnerd, lhames, dblaikie

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D38598

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315069 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed