Modernize doxygen comments in Support/Dwarf.h

In post-commit review of r219442, Rafael pointed out that the comment style
of the newly introduced helper didn't follow LLVM's coding standard.
Modernize the whole file to the new standards.

Differential Revision: http://reviews.llvm.org/D5918

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220467 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed