Handle Error in addOrReplaceDefinition

The only acceptable error is that the symbol cannot be found, in
which case we try to replace it in the next Dylib, or else just add
it to the main Dylib.

Fixes commit 6ab0c926f7 ("[cling] Replace symbols in platform Dylib")

lib/Interpreter/IncrementalJIT.cpp

@@ -682,7 +682,19 @@ IncrementalJIT::addOrReplaceDefinition(StringRef Name,
   bool Defined = false;
   for (auto* Dylib :
        {&Jit->getMainJITDylib(), Jit->getPlatformJITDylib().get()}) {
-    if (Dylib->remove({It->first})) {
+    if (Error Err = Dylib->remove({It->first})) {
+      Err = handleErrors(std::move(Err),
+                         [&](std::unique_ptr<SymbolsNotFound> Err) -> Error {
+                           // This is fine, we will try in the next Dylib.
+                           return Error::success();
+                         });
+
+      if (Err) {
+        logAllUnhandledErrors(std::move(Err), errs(),
+                              "[IncrementalJIT] remove() failed: ");
+        return orc::ExecutorAddr();
+      }
+
       continue;
     }