Remove duplication in expectedFailure* decorators

Differential Revision: http://reviews.llvm.org/D3452


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@206976 91177308-0d34-0410-b5e6-96231b3b80d8
Honour DESTDIR when installing LLDB python module


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@206978 91177308-0d34-0410-b5e6-96231b3b80d8