bpo-30132: distutils test_build_ext() uses temp_cwd() (#1278)
bpo-30132: distutils test_build_ext() uses temp_cwd() (#1278)

test_build_ext() of test_distutils now uses support.temp_cwd() to
prevent the creation of a pdb file in the current working directory
on Windows.
pypa/setuptools,pypa/setuptools,pypa/setuptools