[roll] Roll fuchsia [superproject] Roll llvm-project/libc 7c15455..3e8364f (45 commits)

3e8364f [libc][NFC] fix typo in fenv type proxy headers (#88982)
fe663e0 [libc][fenv] Remove unnecessary dependencies (#88788)
f69dd0a [libc][fenv] Use proxy header (#88787)
69fa8a2 [libc] Add proxy headers for fenv types. (#88467)
8d39b97 [libc][docs] use docgen to generate stdbit rst docs (#88540)
798c4c2 Fix typos (#88565)
58dcf21 Reapply "[libc][math][c23] Add remaining linux/* entrypoints for {,u}fromfp{,x}* (#86692)" (#88567)
dd8e0a4 [libc] add remaining epoll functions, pipe (#84587)
aca7064 [libc] Codify header inclusion policy (#87017)
5fceb41 [libc][docs] Generate docs for signal.h & optimized is_implemented func (#88028)
13d04ef [libc] fix typo in hdr/CMakeLists
3d8dfd1 [libc] Add note to use `LIBC_GPU_BUILD=ON` as another form
2f21e6f Revert "[libc] implement ioctl" (#88226)
a70f657 [libc] implement ioctl (#85890)
1985bb3 [libc] Add proxy header for fenv.h macro constants. #87863 (#87896)
fb97f96 [libc] Initialize rand for fma tests (#88055)
95b2273 [libc] Remove `#ifdef __cplusplus` part from `include/llvm-libc-macros/math-macros.h`. (#87864)
ec6932a [libc][docs] fix missing include
f11a3d6 [libc][docs] generate docs for ctype.h (#87946)
0c054f0 [libc] Remove RandUtils.(h|cpp). (#88044)
05127e9 [libc] Clean up unused math_utils.(h|cpp). (#88036)
ebb1835 [libc] remove MPFR and related tests in full build (#87693)
93eb399 [libc] Increase timeout for death tests. (#87959)
b06d322 [libc] Adding FP_INT_* macro constants if missing in overlay mode. (#87880)
5c8d8d4 [libc][math] Update error bound for log1p to compensate for directional rounding. (#87893)
9596033 [libc] Move statement inside #ifdef/#endif to prevent unused variable warning
cc269b3 [libc] Make `BigInt` bitwise shift consistent with regular integral semantics. (#87874)
bef2fab [libc][NFC] Rename `uint_test` into `big_int_test` for consistency (#87875)
d1ea850 [libc][NFC] Rename `UInt.h` to `big_int.h` and `UInt128.h` to `uint128.h` for consistency (#87808)
a65c90d [libc] Add proxy header math_macros.h. (#87598)
f6162ad [libc][docs] Introduce docgen (#87682)
86154e4 [libc][fenv] Add compile time check (#87826)
920abc0 [libc][support][bit] use new type generic builtins (#86746)
c6b2fac  [libc][c23][fenv] implement fesetexcept  (#87603)
84767d4 reland: [libc] Added transitive bindings for OffsetType (#87680)
d8557aa [libc] Implement roundeven C23 math functions (#87678)
834c1f9 [libc] Temporary math macros fix (#87681)
d049e42 [libc] Move thread sync when closing port earlier
99cdb21 [libc][math][c23] Add exp2m1f C23 math function (#86996)
b46e452 [libc] Fix forward `constexpr` `add_with_carry` / `sub_with_borrow`
8e72d7e [reland][libc] Refactor `BigInt` (#87613)
ddfb24c Revert "[libc] Refactor `BigInt`" (#87612)
cbd7191 [libc] Refactor `BigInt` (#86137)
a5c1fe2 Revert "[libc] Added transitive bindings for OffsetType (#87397)"
b0fcd9b [libc] Added transitive bindings for OffsetType (#87397)

GitOrigin-RevId: 78f020457297f6cd8a9ed49090417d130ba97ca1
Roller-URL: https://ci.chromium.org/b/8750438873882082945
CQ-Do-Not-Cancel-Tryjobs: true
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1029974
Original-Revision: 35c05b38f39a321feef1ee7ee81639d1a190d0bd
Change-Id: I6b01b03250686264cfeb6da2da164d0fc1200116