[iamthehimansh]

What

Part 1 of splitting #8658 into topic PRs, as @adriadam10 asked: the shared-file build fixes that let main compile further on macOS. #4627 (@mugurc) has since landed the Formatting.cpp and ExportMacros.hpp parts, so this PR now carries only what is still missing on main.

Changes, all on macOS only:

• FileStream.hpp: call feof_unlocked / ferror_unlocked unqualified. The macOS SDK defines them as macros, so ::feof_unlocked does not exist.
• StandardExceptions.cpp: const_cast the error-category vtable slot before the function-pointer reinterpret_cast, which Apple clang rejects as casting away qualifiers. Without it libc/src/exception/Exports.cpp fails to build since std::system_category landed.
• ThreadPriority.cpp: macOS has no rtkit or RLIMIT_RTTIME. high asks for the user-interactive QoS class, and rt for a Mach time-constraint policy (period 1 ms, computation 0.5 ms), documented in docs/dev/ENVIRONMENT.md.
• GuestContentSearch.cpp and GuestNpWebApi2.cpp: include <initializer_list>.

On macOS, main still fails 13 objects with this PR. Each is in a file another open macOS PR changes:

File	Open PR
libc/src/GuestAllocations.cpp	fix/macos-guest-allocations-dyld, PR to be opened by @krishalivaibhav
libkernel/DirectMemory/DirectMemory.cpp	#7631
libkernel/Pthread/src/Thread.cpp, System/src/Process.cpp	#7804
libkernel/System/src/Exception.cpp, tests/GuestRaiseException.cpp	#4630
libkernel/File/src/NativeStat.cpp, SharedMemory.cpp, Stdio.cpp, Module/src/DynamicLoader.cpp, ModuleInfo.cpp, System/src/Rtld.cpp	#7201, and the libkernel split PRs of #8658

Why

Upstream CI does not build macOS, so shared headers and new code keep breaking the macOS build of every library. Landing these first keeps the topic PRs from #8658 small, so each can be checked on its own.

Testing

• macOS 26 (Apple M2 Pro, x86_64 under Rosetta, Release, Ninja), on main at a23f8fc9f: the remaining failures are the 13 objects above.
• Linux and Windows compile the same code: every changed file's view under unifdef -U__APPLE__ (with -D__linux__ and with -D_WIN32) equals main.
• python3 tools/check_conventions.py --base origin/main: all checks passed.

Depends on: none. Tracking: #8658.

• One topic
• Conventional Commit title
• No new comments in code
• No GPU code changed

AI-assisted: yes (Cana)

[github-actions]

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