Silence more static analyzer warnings.

Add in definedness checks for shift operators, null checks when
pointers are assumed by the code to be non-null, and explicit
unreachables.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224255 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Object/IRObjectFile.cpp

@@ -181,6 +181,8 @@ void IRObjectFile::moveSymbolNext(DataRefImpl &Symb) const {
     Res = (Index << 2) | 3;
     break;
   }
+  default:
+    llvm_unreachable("unreachable case");
   }
 
   Symb.p = Res;