Really sort the #include lines in unittests/...

I forgot to re-sort after fixing main module headers.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@169244 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/unittests/Lex/LexerTest.cpp b/unittests/Lex/LexerTest.cpp
index ac29ea4..7fca7f4 100644
--- a/unittests/Lex/LexerTest.cpp
+++ b/unittests/Lex/LexerTest.cpp
@@ -8,11 +8,11 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang/Lex/Lexer.h"
-#include "clang/Basic/SourceManager.h"
 #include "clang/Basic/Diagnostic.h"
 #include "clang/Basic/DiagnosticOptions.h"
 #include "clang/Basic/FileManager.h"
 #include "clang/Basic/LangOptions.h"
+#include "clang/Basic/SourceManager.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/Basic/TargetOptions.h"
 #include "clang/Lex/HeaderSearch.h"