[llvm] [CodeGen][NPM] Support generic regalloc-npm option (PR #172485)

[Matt Arsenault via llvm-commits]

================
@@ -1135,32 +1155,76 @@ void CodeGenPassBuilder<Derived, TargetMachineT>::addTargetRegisterAllocator(
     addMachineFunctionPass(RegAllocFastPass(), PMW);
 }
 
+template <typename Derived, typename TargetMachineT>
+template <typename RegAllocPassBuilderT>
+void CodeGenPassBuilder<Derived, TargetMachineT>::addRegAllocPassOrOpt(
+    PassManagerWrapper &PMW, RegAllocPassBuilderT PassBuilder) const {
+  if (auto Err = addRegAllocPassFromOpt(PMW)) {
+    report_fatal_error(std::move(Err));
----------------
arsenm wrote:

```suggestion
    reportFatalUsageError(std::move(Err));
```

https://github.com/llvm/llvm-project/pull/172485