rdar://problem/10492827

SBProcess.GetSTDERR() not getting stderr of the launched process

Since we are launch the inferior with:

    process = target.LaunchSimple(None, None, os.getcwd())

i.e., without specifying stdin/out/err.  A pseudo terminal is used for
handling the process I/O, and we are satisfied once the expected output
appears in process.GetSTDOUT().

llvm-svn: 147983