add register name to UnwindLog error message

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@189062 91177308-0d34-0410-b5e6-96231b3b80d8
Round plt entsize to addralign

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@189066 91177308-0d34-0410-b5e6-96231b3b80d8