Remove useless dynamic_cast<>().

Thanks Peter for pointing me to something that should have never been
committed to the llvm code base.

llvm-svn: 121648
diff --git a/llvm/lib/Analysis/RegionPass.cpp b/llvm/lib/Analysis/RegionPass.cpp
index a4145e1..3269dcc 100644
--- a/llvm/lib/Analysis/RegionPass.cpp
+++ b/llvm/lib/Analysis/RegionPass.cpp
@@ -259,8 +259,7 @@
 
     // [3] Assign manager to manage this new manager. This may create
     // and push new managers into PMS
-    Pass *P = dynamic_cast<Pass *>(RGPM);
-    TPM->schedulePass(P);
+    TPM->schedulePass(RGPM);
 
     // [4] Push new manager into PMS
     PMS.push(RGPM);