fixed the way the cfg file markers values are split under win32

Lib/packaging/config.py

@@ -21,7 +21,8 @@ def _pop_values(values_dct, key):
     if not vals_str:
         return
     fields = []
-    for field in vals_str.split(os.linesep):
+    # the line separator is \n for setup.cfg files
+    for field in vals_str.split('\n'):
         tmp_vals = field.split('--')
         if len(tmp_vals) == 2 and not interpret(tmp_vals[1]):
             continue

Lib/packaging/tests/test_config.py

@@ -307,7 +307,7 @@ class ConfigTestCase(support.TempdirManager,
             ['/usr/include/gecode', '/usr/include/blitz'])
         cargs = ['-fPIC', '-O2']
         if sys.platform == 'win32':
-            cargs.append("/DGECODE_VERSION='win32'")
+            cargs.append("/DGECODE_VERSION=win32")
         else:
             cargs.append('-DGECODE_VERSION=$(./gecode_version)')
         self.assertEqual(ext.extra_compile_args, cargs)