llvm: update remarks support on LLVM 22

LLVM change dfbd76bda01e removed separate remark support entirely, but
it turns out we can just drop the parameter and everything appears to
work fine.

Fixes 146912 as far as I can tell (the test passes.)

@rustbot label llvm-main

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -1779,9 +1779,14 @@ extern "C" void LLVMRustContextConfigureDiagnosticHandler(
     // Do not delete the file after we gather remarks
     RemarkFile->keep();
 
+#if LLVM_VERSION_GE(22, 0)
+    auto RemarkSerializer = remarks::createRemarkSerializer(
+        llvm::remarks::Format::YAML, RemarkFile->os());
+#else
     auto RemarkSerializer = remarks::createRemarkSerializer(
         llvm::remarks::Format::YAML, remarks::SerializerMode::Separate,
         RemarkFile->os());
+#endif
     if (Error E = RemarkSerializer.takeError()) {
       std::string Error = std::string("Cannot create remark serializer: ") +
                           toString(std::move(E));