When specifying a relative path for the --framework option to dotest.py,...

When specifying a relative path for the --framework option to dotest.py, Python would end up being confused and unable to locate the embedded_interpreter module, causing every testcase that uses the Script Interpreter (e.g. functionalities/data-formatter/data-formatter-stl/libstdcpp) to fail without even trying
This checkin fixes that problem by absolutizing the path before pushing it to the sys.path

llvm-svn: 179341