Sort all of Clang's files under 'lib', and fix up the broken headers
uncovered.

This required manually correcting all of the incorrect main-module
headers I could find, and running the new llvm/utils/sort_includes.py
script over the files.

I also manually added quite a few missing headers that were uncovered by
shuffling the order or moving headers up to be main-module-headers.

llvm-svn: 169237
diff --git a/clang/lib/Lex/PPExpressions.cpp b/clang/lib/Lex/PPExpressions.cpp
index d5a88db..868f2dd 100644
--- a/clang/lib/Lex/PPExpressions.cpp
+++ b/clang/lib/Lex/PPExpressions.cpp
@@ -17,11 +17,11 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang/Lex/Preprocessor.h"
-#include "clang/Lex/MacroInfo.h"
-#include "clang/Lex/LiteralSupport.h"
-#include "clang/Lex/CodeCompletionHandler.h"
 #include "clang/Basic/TargetInfo.h"
+#include "clang/Lex/CodeCompletionHandler.h"
 #include "clang/Lex/LexDiagnostic.h"
+#include "clang/Lex/LiteralSupport.h"
+#include "clang/Lex/MacroInfo.h"
 #include "llvm/ADT/APSInt.h"
 #include "llvm/Support/ErrorHandling.h"
 using namespace clang;