Use cast<> instead of unchecked dyn_cast<>

llvm-svn: 218085
diff --git a/llvm/lib/IR/DataLayout.cpp b/llvm/lib/IR/DataLayout.cpp
index 3887353..7496268 100644
--- a/llvm/lib/IR/DataLayout.cpp
+++ b/llvm/lib/IR/DataLayout.cpp
@@ -641,7 +641,7 @@
             ? getPointerABIAlignment(0)
             : getPointerPrefAlignment(0));
   case Type::PointerTyID: {
-    unsigned AS = dyn_cast<PointerType>(Ty)->getAddressSpace();
+    unsigned AS = cast<PointerType>(Ty)->getAddressSpace();
     return (abi_or_pref
             ? getPointerABIAlignment(AS)
             : getPointerPrefAlignment(AS));