Shorten DiagnosticInfoOptimizationRemark* to OptimizationRemark*. NFC

With the new streaming interface, these class names need to be typed a
lot and it's way too looong.

llvm-svn: 282544
diff --git a/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp b/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp
index 69c5226..7ef5f24 100644
--- a/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp
+++ b/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp
@@ -710,7 +710,7 @@
   if (FL.empty())
     return false;
   const Function &Fn = FL.front();
-  auto DI = DiagnosticInfoOptimizationRemark(DEBUG_TYPE, Fn, DebugLoc(), "");
+  auto DI = OptimizationRemark(DEBUG_TYPE, Fn, DebugLoc(), "");
   return DI.isEnabled();
 }