[dwarfdump] Make incompatibility between -diff and -verbose explicit.

Using -diff and -verbose together doesn't work today. We should audit
where these two options interact and fix them. In the meantime we error
out when the user try to specify both.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@345084 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed