Rename OptimizationDiagnosticInfo.* to OptimizationRemarkEmitter.*

Sync it up with the name of the class actually defined here.  This has been
bothering me for a while...

llvm-svn: 315249
diff --git a/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp b/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp
index c730858..ec34deb 100644
--- a/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp
+++ b/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp
@@ -51,7 +51,7 @@
 #include "llvm/ADT/iterator_range.h"
 #include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/Analysis/BasicAliasAnalysis.h"
-#include "llvm/Analysis/OptimizationDiagnosticInfo.h"
+#include "llvm/Analysis/OptimizationRemarkEmitter.h"
 #include "llvm/Analysis/TypeMetadataUtils.h"
 #include "llvm/IR/CallSite.h"
 #include "llvm/IR/Constants.h"