[KernelInfo] Adjust for PR llvm#96691 upstreaming changes

The original version was introduced here in 2476cd3.

Author: jdenny-ornl

llvm/lib/LTO/LTOBackend.cpp

@@ -191,13 +191,8 @@ static void RegisterPassPlugins(ArrayRef<std::string> PassPlugins,
   // Load requested pass plugins and let them register pass builder callbacks
   for (auto &PluginFN : PassPlugins) {
     auto PassPlugin = PassPlugin::Load(PluginFN);
-    if (!PassPlugin) {
-      errs() << "Failed to load passes from plugin '" << PluginFN
-             << "' (request ignored): " << toString(PassPlugin.takeError())
-             <<  "\n";
-      continue;
-    }
-
+    if (!PassPlugin)
+      report_fatal_error(PassPlugin.takeError(), /*gen_crash_diag=*/false);
     PassPlugin->registerPassBuilderCallbacks(PB);
   }
 }

llvm/test/Feature/load_plugin_error.ll

@@ -1,10 +1,10 @@
-; REQUIRES: plugins
+; REQUIRES: plugins, x86-registered-target
 ; UNSUPPORTED: target={{.*windows.*}}
 
 ; RUN: not opt < %s -load-pass-plugin=%t/nonexistent.so -disable-output 2>&1 | FileCheck %s
 
 ; RUN: opt %s -o %t.o
-; RUN: llvm-lto2 run -load-pass-plugin=%t/nonexistent.so %t.o -o %t \
+; RUN: not llvm-lto2 run -load-pass-plugin=%t/nonexistent.so %t.o -o %t \
 ; RUN:     -r %t.o,test 2>&1 | \
 ; RUN:   FileCheck %s