Revert "Add a missing reference on a std::vector<> out param"
Revert "[Support] Propagate the environment into the test child process"

This reverts commit r180046.
This reverts commit r180041.

These have broken buildbots for ~3 hours:

http://lab.llvm.org:8013/builders/clang-x86_64-darwin11-nobootstrap-RAincremental/builds/763