llvm-readobj: Handle invalid references to the string table.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242658 91177308-0d34-0410-b5e6-96231b3b80d8

tools/llvm-readobj/llvm-readobj.h

@@ -19,6 +19,7 @@ namespace llvm {
   }
 
   // Various helper functions.
+  void reportError(Twine Msg);
   void error(std::error_code ec);
   bool relocAddressLess(object::RelocationRef A,
                         object::RelocationRef B);