simple plugin now works with Linux fix assert in SetPluginInfo implement Linux ePathTypeLLDBSystemPlugins and ePathTypeLLDBUserPlugins implement Linux Host::Backtrace and Host::GetEnvironment add .gnu_debugdata comment

Differential Revision: http://llvm-reviews.chandlerc.com/D1159

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@186475 91177308-0d34-0410-b5e6-96231b3b80d8