[roll] Roll fuchsia [superproject] Roll llvm-project/libc 365bc3f..b5b1e8f (14 commits)

b5b1e8f [libc] Use `rint` builtin for rounding on the GPU (#98345)
27223f5 [libc] Add a missing math-function-macros.h include (#98271)
ab3e2e4 [libc] Provide isnan, isnanf and isnanl functions (#96008)
58de9c1 [libc] Add support for `powi` as an LLVM libc extension on the GPU (#98236)
649fe69 [libc][math] Fix overflow shifts for dyadic floats and add skip accuracy option for expm1. (#98048)
33ac8c5 Revert "[libc] Move off_t and stdio macros to proxy hdrs" (#98242)
d774fae [libc] Move the internal extern "C" symbols inside the namespace (#98232)
821c94e [libc] Move off_t and stdio macros to proxy hdrs (#98215)
72c0621 [libc] Fix sprintf FixedConv test (#98204)
a88ab5c [libc] Fix readlink tests on 32-bit systems (#98168)
c68ccae [libc] adjust printf macro test to use all 64 bits (#98195)
4abbacf [libc] Include stdio.h in baremetal getchar.cpp (#98188)
fb70a0b [libc] Avoid the atexit and exit_handler dependency for exit (#98121)
c9066d2 [libc] Disable `-ffreestanding` and `-fno-builtin` on the GPU build (#97636)

GitOrigin-RevId: 705281ffae3827e9cb93dbe62de94ca54e50a353
Roller-URL: https://ci.chromium.org/b/8742764132588221137
CQ-Do-Not-Cancel-Tryjobs: true
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1079553
Original-Revision: ca95a2fc133657ba2410529a1c30a03ad1c32786
Change-Id: I4a3015c072a6a4a7f01f19052678d3a241216db4