[llvm-cxxdump] Use error reporting helpers from support

This patch makes llvm-cxxdump use the error reporting helpers from
Support/WithColor.h

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@346602 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed