Revert "Fix Windows tests when __config_site is present."

It's 2017, and line endings are still an issue.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@302496 91177308-0d34-0410-b5e6-96231b3b80d8

utils/libcxx/test/config.py

@@ -546,7 +546,6 @@ class Configuration(object):
 
     def configure_compile_flags_header_includes(self):
         support_path = os.path.join(self.libcxx_src_root, 'test', 'support')
-        self.configure_config_site_header()
         if self.cxx_stdlib_under_test != 'libstdc++' and \
            not self.is_windows:
             self.cxx.compile_flags += [
@@ -562,6 +561,7 @@ class Configuration(object):
                 '-include', os.path.join(support_path,
                                          'set_windows_crt_report_mode.h')
             ]
+        self.configure_config_site_header()
         cxx_headers = self.get_lit_conf('cxx_headers')
         if cxx_headers == '' or (cxx_headers is None
                                  and self.cxx_stdlib_under_test != 'libc++'):