[Polly] Fix using order, as this caused a test failure (NFC)

[fhahn]

Summary

Without this patch, clang-format in check-polly fails for me, with current master:

FAILED: cd build/tools/polly && build/bin/clang-format -sort-includes -style=llvm llvm/tools/polly/include/polly/ScopPass.h | diff -u llvm/tools/polly/include/polly/ScopPass.h -
--- llvm/tools/polly/include/polly/ScopPass.h	2017-11-06 14:05:49.885345000 +0000
+++ -	2017-11-06 14:07:24.956241758 +0000
@@ -40,12 +40,12 @@
 } // namespace polly

 namespace llvm {
+using polly::SPMUpdater;
 using polly::Scop;
 using polly::ScopAnalysisManager;
 using polly::ScopAnalysisManagerFunctionProxy;
 using polly::ScopInfo;
 using polly::ScopStandardAnalysisResults;
-using polly::SPMUpdater;

 template <>
 class InnerAnalysisManagerProxy<ScopAnalysisManager, Function>::Result {

[Meinersbur]

LGTM, fails for me too. Probably caused by change in clang-format: rL317325

include/polly/ScopPass.h

 } // namespace polly
 
 namespace llvm {
+using polly::SPMUpdater;
 using polly::Scop;
 using polly::ScopAnalysisManager;
 using polly::ScopAnalysisManagerFunctionProxy;
 using polly::ScopInfo;
 using polly::ScopStandardAnalysisResults;
-using polly::SPMUpdater;
 
 template <>
 class InnerAnalysisManagerProxy<ScopAnalysisManager, Function>::Result {