[Codegen][NFC] Replace 'RegisterRegAlloc::FunctionPassCtor' with 'RegisterRegAllocBase<T>::FunctionPassCtor' .

[Jimerlife]

Summary

Use RegisterRegAllocBase<T>::FunctionPassCtor to construct RegisterRegAllocBase<T>::Registry maybe more proper.

[RKSimon]

Out of curiosity - what motivated this change? Do you have dependent patches you're developing or did a linter recommend it?

[Jimerlife]

In D145032#4160993, @RKSimon wrote:

Out of curiosity - what motivated this change? Do you have dependent patches you're developing or did a linter recommend it?

RegisterRegAlloc, SGPRRegisterRegAlloc and VGPRRegisterRegAlloc are all subclass of RegisterRegAllocBase. There will be construct three Registry, like RegisterRegAllocBase<RegisterRegAlloc>::Registry, RegisterRegAllocBase<SGPRRegisterRegAlloc>::Registry, RegisterRegAllocBase<VGPRRegisterRegAlloc>::Registry. So, I think it is more appropriate to use the FunctionPassCtor of the parent class to replace the FunctionPassCtor of the child class(RegisterRegAlloc).

[arsenm]

Don't see any real difference here

llvm/include/llvm/CodeGen/RegAllocRegistry.h

 class RegisterRegAlloc : public RegisterRegAllocBase<RegisterRegAlloc> {
 public:
   RegisterRegAlloc(const char *N, const char *D, FunctionPassCtor C)
     : RegisterRegAllocBase(N, D, C) {}
 };
 
 /// RegisterRegAlloc's global Registry tracks allocator registration.
 template <class T>
-MachinePassRegistry<RegisterRegAlloc::FunctionPassCtor>
+MachinePassRegistry<typename RegisterRegAllocBase<T>::FunctionPassCtor>
 RegisterRegAllocBase<T>::Registry;
 
 } // end namespace llvm
 
 #endif // LLVM_CODEGEN_REGALLOCREGISTRY_H