[clang] [llvm] MCAsmStreamer: Replace the MCInstPrinter * parameter with unique_ptr (PR #135128)

[Fangrui Song via cfe-commits]

MaskRay wrote:

> Thanks for improving code health! :-)
> 
> LGTM but I'm not familiar with this area of LLVM nor a code owner, so I'll defer to the code owners.
> 
> Nit: this patch does a few drive-by fixes (deletes the createAsmStreamer variant with three bools; rename to createSystemZAsmStreamer), which are not mentioned in the patch description.

Thanks for checking! Updated description about SystemZ (to fix an overload resolution conflict).

The deprecated overload should be removed separately. I will do that and rebase this PR if renaming createAsmStreamer looks good.
```
MCStreamer *Target::createAsmStreamer(MCContext &Ctx,
                                      std::unique_ptr<formatted_raw_ostream> OS,
                                      bool IsVerboseAsm, bool UseDwarfDirectory,
                                      MCInstPrinter *IP,
                                      std::unique_ptr<MCCodeEmitter> &&CE,
                                      std::unique_ptr<MCAsmBackend> &&TAB,
                                      bool ShowInst) const {
  return createAsmStreamer(Ctx, std::move(OS), IP, std::move(CE),
                           std::move(TAB));
}
```

https://github.com/llvm/llvm-project/pull/135128