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/Tooling/CompilationDatabase.cpp b/clang/lib/Tooling/CompilationDatabase.cpp
index ebdb965..e62a6f7 100644
--- a/clang/lib/Tooling/CompilationDatabase.cpp
+++ b/clang/lib/Tooling/CompilationDatabase.cpp
@@ -12,13 +12,13 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include <sstream>
 #include "clang/Tooling/CompilationDatabase.h"
 #include "clang/Tooling/CompilationDatabasePluginRegistry.h"
 #include "clang/Tooling/Tooling.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/system_error.h"
+#include <sstream>
 
 namespace clang {
 namespace tooling {