Revert "[lldb][ObjC] Don't query objective-c runtime for decls in C++ contexts (#95963)"

This reverts commit dadf960.

The commit caused `TestEarlyProcessLaunch.py` to fail on the
macOS bots.

Author: Michael137

lldb/source/Plugins/ExpressionParser/Clang/ClangASTSource.cpp

@@ -637,7 +637,7 @@ void ClangASTSource::FindExternalVisibleDecls(
     FindDeclInModules(context, name);
   }
 
-  if (!context.m_found_type && m_ast_context->getLangOpts().ObjC) {
+  if (!context.m_found_type) {
     FindDeclInObjCRuntime(context, name);
   }
 }

lldb/test/API/lang/objcxx/objc-from-cpp-frames-without-debuginfo/TestObjCFromCppFramesWithoutDebugInfo.py

@@ -15,11 +15,4 @@ def test(self):
         (_, process, _, _) = lldbutil.run_to_name_breakpoint(self, "main")
 
         self.assertState(process.GetState(), lldb.eStateStopped)
-
-        # Tests that we can use builtin Objective-C identifiers.
         self.expect("expr id", error=False)
-
-        # Tests that we can lookup Objective-C decls in the ObjC runtime plugin.
-        self.expect_expr(
-            "NSString *c; c == nullptr", result_value="true", result_type="bool"
-        )