[roll] Roll fuchsia Revert "[libc] Roll llvm-project/libc 2f8c3219c..fe8e3feb2"

This reverts commit d7b2efed5e0c49c034fb5ab1fc1e1a8cfb94099e.

Reason for revert: Tree closure https://fxbug.dev/473840785

Original change's description:
> [libc] Roll llvm-project/libc 2f8c3219c..fe8e3feb2
>
> Manual roll with new include-preempt/src/__support/CPP/tuple.h
> and include-preempt/src/__support/CPP/new.h headers needed due to
> upstream `std` references.
>
> Includes new include-preempt/src/__support/macros/attributes.h  to
> work around an RBE bug (https://fxbug.dev/471248163).
>
> //third_party/llvm-libc/src https://llvm.googlesource.com/llvm-project/libc/+log/2f8c3219c..fe8e3feb2
> fe8e3feb2 Reland Refactor WIDE_READ to allow finer control over high-performance function selection (#165613) (#170738)
> 1546c0b8d Revert "Refactor WIDE_READ to allow finer control over high-performance function selection" (#170717)
> 8d496343a Refactor WIDE_READ to allow finer control over high-performance function selection (#165613)
> 2894029a3 [libc][math] Refactor expm1 implementation to header-only in src/__support/math folder. (#162127)
> d1a98a113 [libc][wctype] Add cmake flag for configuring wctype implementation used (#170531)
> 97ad1bdc0 [libc] make clock_conversion.h common and document it (#167723)
> 81cb307aa [libc][malloc] Ensure a minimum block alignment of 4 (#169447)
> 4edd91910 [libc][docs] Add links to 2025 talks. (#170206)
> 9a7e7a020 [libc] Remove btowc / wctob from wctype_utils internal header. (#170200)
> 972ed9f89 [libc] Add clock_gettime for Darwin (#167160)
> 2863715e2 [libc][darwin] add internal::exit (#166357)
> 81b392d41 [libc][test] split exit tests into two separate tests (#169820)
> c99de1f3d [libc][darwin] add syscall numbers from macos sdk (#166354)
> 3e7cabf2e [libc] Add missing dependencies for arpa/inet.h header. (#168951)
> 5e389e2e7 [libc] Removed unused flags from baremetal cache files (#168942)
> 33401772d [libc][math] Add float-only implementation for atanf. (#167004)
>
> Original-Bug: 471248163
> Cq-Include-Trybots: luci.turquoise.global.try:run-postsubmit-tryjobs
> Change-Id: Iadb65238f39b471a67758265a0db7f5c4ae3d76e
> Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1455149
> Reviewed-by: Paul Kirth <paulkirth@google.com>
> Reviewed-by: David Fang <fangism@google.com>
> Fuchsia-Auto-Submit: Roland McGrath <mcgrathr@google.com>
> Commit-Queue: Roland McGrath <mcgrathr@google.com>

Original-Bug: 471248163
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1468231
Exempt: RubberStamper 🤖 <android-build-ayeaye@system.gserviceaccount.com>
Original-Revision: a8233835f80c4738ef2f3b99b1060da4f381bb24
GitOrigin-RevId: 92539d25ce4d17f9344a8249eeec228e98b4c8f3
Change-Id: I74e3327ff857fca0f36f24c86640988da45d4389