Fix a copy-and-paste mistake. Give the pass a real name. NFC.

Swift SVN r20945

lib/SILPasses/Devirtualizer.cpp

@@ -1021,7 +1021,7 @@ namespace {
       }
     }
 
-    StringRef getName() override { return "Devirtualization"; }
+    StringRef getName() override { return "Inline Caches"; }
   };
 
 } // end anonymous namespace