[JIT] Fix crash in unit tests

The unit tests `ReOptimizeLayerTest.BasicReOptimization` and `JITLinkRedirectionManagerTest.BasicRedirectionOperation` are failing for me with the error:

```
Program aborted due to an unhandled Error:
Error value was Success. (Note: Success values must still be checked prior to being destroyed).
```

The error is raised when a value is assigned to `Err`, due to the the missing `ErrorAsOutParameter`.

Author: redstar

llvm/include/llvm/ExecutionEngine/Orc/JITLinkRedirectableSymbolManager.h

@@ -59,6 +59,7 @@ class JITLinkRedirectableSymbolManager : public RedirectableSymbolManager,
             ObjLinkingLayer.getExecutionSession().getTargetTriple())),
         PtrJumpStubCreator(jitlink::getPointerJumpStubCreator(
             ObjLinkingLayer.getExecutionSession().getTargetTriple())) {
+    ErrorAsOutParameter _(&Err);
     if (!AnonymousPtrCreator || !PtrJumpStubCreator)
       Err = make_error<StringError>("Architecture not supported",
                                     inconvertibleErrorCode());