Reapply "[libc++][streams] P1759R6: Native handles and file streams" (#77190)

Fixes build on Windows in C++26 mode.

Reverted in:
https://github.com/llvm/llvm-project/commit/40c07b559aa6ab4bac074c943967d3207bc07ae0
Original PR: https://github.com/llvm/llvm-project/pull/76632



---------

Co-authored-by: Zingam <zingam@outlook.com>