[lldb][DataFormatter] Format libstdc++ unique_ptr like we do libc++ (#146909)

The only difference is that with libc++ the summary string contains the
derefernced pointer value. With libstdc++ we currently display the
pointer itself, which seems redundant. E.g.,
```
(std::unique_ptr<int>) iup = 0x55555556d2b0 {
  pointer = 0x000055555556d2b0
}
(std::unique_ptr<std::basic_string<char> >) sup = 0x55555556d2d0 {
  pointer = "foobar"
}
```

This patch moves the logic into a common helper that's shared between
the libc++ and libstdc++ formatters.

After this patch we can combine the libc++ and libstdc++ API tests (see
https://github.com/llvm/llvm-project/pull/146740).

0 files changed, 0 insertions, 0 deletions