Use -Wl to specify -rpath correctly.

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@187431 91177308-0d34-0410-b5e6-96231b3b80d8
Add missing -Xlinker to order test.

Both the parameter itself and the argument to the parameter must be prefixed
with -Xlinker so that they are passed properly.

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@187432 91177308-0d34-0410-b5e6-96231b3b80d8