Added the capability for the test driver to relocate the tests and the intermediate

files to a different top level directory than those specified on the command line.

When relocated, the test clanups normally performed afterwards after each test method
and after each test class will not be exercised at all.  This allows for an easier
postmortem analysis of test failures.

Example:

./dotest.py -v -t -r /tmp/lldbtest types

will create a /tmp/lldbtest directory which houses the types directory and its supported
files.

Files modified:

o dotest.py, lldbtest.py:

  Add logic to process '-r dir' option to support relocating the tests to a different
  top level directory instead of exected in place.

o darwin.py, test/types/Makefile:

  The 'make clean' should only clean the minimum .o and .d files.

llvm-svn: 116255