[LTO] Move UpdateCompilerUsed.h from lib/ to include/

I plan to use it in lld soon.

Differential Revision:  http://reviews.llvm.org/D21575

llvm-svn: 273380
diff --git a/llvm/lib/LTO/UpdateCompilerUsed.cpp b/llvm/lib/LTO/UpdateCompilerUsed.cpp
index bed784a..1177308 100644
--- a/llvm/lib/LTO/UpdateCompilerUsed.cpp
+++ b/llvm/lib/LTO/UpdateCompilerUsed.cpp
@@ -11,11 +11,10 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "UpdateCompilerUsed.h"
-
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/Mangler.h"
+#include "llvm/LTO/UpdateCompilerUsed.h"
 #include "llvm/Target/TargetLowering.h"
 #include "llvm/Target/TargetSubtargetInfo.h"
 #include "llvm/Transforms/IPO/Internalize.h"