[libcxx-commits] [libcxx] [libc++][NFC] Remove `pointer_traits<__wrap_iter>` partial specialization (PR #178864)

[A. Jiang via libcxx-commits]

frederick-vs-ja wrote:

@philnik777 I've tested this on Godbolt.

Compiler:
x86-64 clang (trunk)

Tested program, with old or new contents of `<__iterator/wrap_iter.h>`:
```C++
/* copy-and-paste old or new contents of <__iterator/wrap_iter.h> */

#include <vector>

int main() {
  std::vector<int> v{};
}
```

Command options:
- `-std=c++26 -stdlib=libc++ -pedantic-errors -ftime-report`
- `-std=c++26 -stdlib=libc++ -O2 -pedantic-errors -ftime-report`

Average total time:
- Old: 0.721085
- Old, `-O2`: 0.807295
- New: 0.718795 (reduced by ~0.3%)
- New, `-O2`: 0.739025 (reduced by ~8.5%).

I think we can conclude that there is not negative impact.

https://github.com/llvm/llvm-project/pull/178864