remove trailing whitespace + remove some useless comments

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@212411 91177308-0d34-0410-b5e6-96231b3b80d8
llvm::IntrusiveRefCntPtr => std::shared_ptr to match the changes in clang r212388

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@212413 91177308-0d34-0410-b5e6-96231b3b80d8