[NFC] Header cleanup

Summary: Removed unused headers, replaced some headers with forward class declarations

Patch by: Eugene <claprix@yandex.ru>

Differential Revision: https://reviews.llvm.org/D20100

llvm-svn: 275882
diff --git a/clang/tools/libclang/Indexing.cpp b/clang/tools/libclang/Indexing.cpp
index fe14cb2..878d75e 100644
--- a/clang/tools/libclang/Indexing.cpp
+++ b/clang/tools/libclang/Indexing.cpp
@@ -26,7 +26,7 @@
 #include "clang/Lex/PPCallbacks.h"
 #include "clang/Lex/PPConditionalDirectiveRecord.h"
 #include "clang/Lex/Preprocessor.h"
-#include "clang/Sema/SemaConsumer.h"
+#include "clang/Lex/PreprocessorOptions.h"
 #include "llvm/Support/CrashRecoveryContext.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/Mutex.h"