[APINotes] Remove unused includes (NFC) (#142406)

These are identified by misc-include-cleaner.  I've filtered out those
that break builds.  Also, I'm staying away from llvm-config.h,
config.h, and Compiler.h, which likely cause platform- or
compiler-specific build failures.

clang/lib/APINotes/APINotesManager.cpp

@@ -15,9 +15,7 @@
 #include "clang/Basic/Module.h"
 #include "clang/Basic/SourceManager.h"
 #include "clang/Basic/SourceMgrAdapter.h"
-#include "clang/Basic/Version.h"
 #include "llvm/ADT/APInt.h"
-#include "llvm/ADT/Hashing.h"
 #include "llvm/ADT/SetVector.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallVector.h"

clang/lib/APINotes/APINotesReader.cpp

@@ -16,10 +16,8 @@
 #include "APINotesFormat.h"
 #include "clang/APINotes/Types.h"
 #include "llvm/ADT/Hashing.h"
-#include "llvm/ADT/StringExtras.h"
 #include "llvm/Bitstream/BitstreamReader.h"
 #include "llvm/Support/DJB.h"
-#include "llvm/Support/EndianStream.h"
 #include "llvm/Support/OnDiskHashTable.h"
 
 namespace clang {