PassWrapper: adapt for llvm/llvm-project@b01e2a8

We don't see a reason to explicitly pass the default here, so just use
the default instead of explicitly passing it and needing an ifdef.

@rustbot label: +llvm-main

compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp

@@ -827,9 +827,9 @@ extern "C" LLVMRustResult LLVMRustOptimize(
       !NoPrepopulatePasses) {
     PipelineStartEPCallbacks.push_back(
         [](ModulePassManager &MPM, OptimizationLevel Level) {
-          MPM.addPass(LowerTypeTestsPass(/*ExportSummary=*/nullptr,
-                                         /*ImportSummary=*/nullptr,
-                                         /*DropTypeTests=*/false));
+          MPM.addPass(LowerTypeTestsPass(
+              /*ExportSummary=*/nullptr,
+              /*ImportSummary=*/nullptr));
         });
   }