Re-sort #include lines for unittests. This uses a slightly modified
clang-format (https://reviews.llvm.org/D33932) to keep primary headers
at the top and handle new utility headers like 'gmock' consistently with
other utility headers.

No other change was made. I did no manual edits, all of this is
clang-format.

This should allow other changes to have more clear and focused diffs,
and is especially motivated by moving some headers into more focused
libraries.

llvm-svn: 304786
diff --git a/llvm/unittests/ADT/HashingTest.cpp b/llvm/unittests/ADT/HashingTest.cpp
index b28561b..367f58d 100644
--- a/llvm/unittests/ADT/HashingTest.cpp
+++ b/llvm/unittests/ADT/HashingTest.cpp
@@ -11,9 +11,9 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "gtest/gtest.h"
 #include "llvm/ADT/Hashing.h"
 #include "llvm/Support/DataTypes.h"
+#include "gtest/gtest.h"
 #include <deque>
 #include <list>
 #include <map>