ObjectFile makeTriple - silence static analyzer dyn_cast<COFFObjectFile> null dereference warning. NFCI.

The static analyzer is warning about a potential null dereference, but we should be able to use cast<COFFObjectFile> directly and if not assert will fire for us.

llvm-svn: 373324

Author: RKSimon

llvm/lib/Object/ObjectFile.cpp

@@ -105,7 +105,7 @@ Triple ObjectFile::makeTriple() const {
     TheTriple.setObjectFormat(Triple::MachO);
 
   if (isCOFF()) {
-    const auto COFFObj = dyn_cast<COFFObjectFile>(this);
+    const auto COFFObj = cast<COFFObjectFile>(this);
     if (COFFObj->getArch() == Triple::thumb)
       TheTriple.setTriple("thumbv7-windows");
   }