[roll] Roll llvm-project/libc [libc] Added support for fixed-points in ``is_signed`` and ``is_unsigned``. (#133371)

Fixes #133365

## Changes Done
- Changed the signed checking to
```cpp
struct is_signed : bool_constant<((is_fixed_point<T> || is_arithmetic_v<T>) && (T(-1) < T(0)))>
```
in ``/libc/src/__support/CPP/type_traits/is_signed.h``. Added check for
fixed-points.
- But, got to know that this will fail for ``unsigned _Fract`` or any
unsigned fixed-point because ``unsigned _Fract`` can’t represent -1 in
T(-1), while ``unsigned int`` can handle it via wrapping.
- That's why I explicity added ``is_signed`` check for ``unsigned``
fixed-points.
- Same changes to ``/libc/src/__support/CPP/type_traits/is_unsigned.h``.
- Added tests for ``is_signed`` and ``is_unsigned``.

GitOrigin-RevId: 444425f7de7c6a703e3baebde657fd596b3499b0
Original-Revision: 53b8c52927991cbcd4f7ec43c976ac477baae813
Change-Id: I9c429ea3005aa0df5b4a4cb2ff38a909c2000143
1 file changed
tree: 064a9b3e3388456066d4aa3a1a6f055eb27a07e5
  1. ctf/
  2. git-hooks/
  3. infra/
  4. third_party/
  5. cts
  6. firmware
  7. flower
  8. jiri.lock
  9. MILESTONE
  10. minimal
  11. prebuilts
  12. README.md
  13. stem
  14. test_durations
  15. toolchain
README.md

Integration

This repository contains Fuchsia's Global Integration manifest files.

Making changes

All changes should be made to the internal version of this repository. Our infrastructure automatically updates this version when the internal one changes.

Currently all changes must be made by a Google employee. Non-Google employees wishing to make a change can ask for assistance in one of the communication channels documented at get involved.

Obtaining the source

First install Jiri.

Next run:

$ jiri init
$ jiri import minimal https://fuchsia.googlesource.com/integration
$ jiri update

Third party

Third party projects should have their own subdirectory in ./third_party.