[llvm] [PassInstrumentation] Make getPassNameForClassName return optional (PR #150029)

[Nikita Popov via llvm-commits]

================
@@ -534,7 +534,7 @@ bool llvm::runPassPipeline(
     raw_string_ostream SOS(Pipeline);
     MPM.printPipeline(SOS, [&PIC](StringRef ClassName) {
       auto PassName = PIC.getPassNameForClassName(ClassName);
-      return PassName.empty() ? ClassName : PassName;
+      return PassName ? ClassName : *PassName;
----------------
nikic wrote:

```suggestion
      return !PassName ? ClassName : *PassName;
```

https://github.com/llvm/llvm-project/pull/150029