Prevent using TESTDIR environment variable as it contains Unix-style path when run from or_tests.bash, which causes problems on Windows.
Prevent using TESTDIR environment variable
as it contains Unix-style path when run from or_tests.bash,
which causes problems on Windows.

bodob/OpenROAD_UnitTestFramework,clach04/OpenROAD_UnitTestFramework,ActianCorp/OpenROAD_UnitTestFramework