llvm-project Meso-Update

[StephanTLavavej]

• This updates our llvm-project submodule for the first time in 4 months. Previously:
  • llvm-project Mega-Update #4263
  • llvm-project Mini-Update #4348
• To make this possible, I had to fix the following things upstream:
  • [libc++] Mark P2845R8 __cpp_lib_format_path and P2587R3 __cpp_lib_to_string as C++26 llvm/llvm-project#93255
  • [libc++] [test] Fix MSVC warnings llvm/llvm-project#93257
  • [libc++] [test] Fix portability issues for MSVC llvm/llvm-project#93259
• Tons of things have been fixed upstream, allowing us to remove many expected failures and update comments:
  • [libc++] LWG2381: Inconsistency in parsing floating point numbers llvm/llvm-project#77948
  • [libc++][memory] P2652R2: Disallow Specialization of allocator_traits llvm/llvm-project#79978
  • [libc++] Avoid including libc++ private header in std/ test llvm/llvm-project#79856
  • [libc++][test] Don't include test_format_context.h in parse.pass.cpp llvm/llvm-project#83734
  • [libc++] P2602R2 Poison Pills are Too Toxic llvm/llvm-project#74534
  • [libc++] Adjust some of the [rand.dist] critical values that are too strict llvm/llvm-project#88669
  • [libc++][test] Fixes constexpr char_traits. llvm/llvm-project#90981
  • [libc++][pstl] Improve exception handling llvm/llvm-project#88998
  • [libc++] Fix incomplete user-defined ctype specialization in test llvm/llvm-project#74630
  • [libc++][test] Fix MSVC warning C4127 in array.cons/initialization.pass.cpp llvm/llvm-project#79793
• libcxx replaced old Features with 'has-1024-bit-atomics' (and unconditional Features should be defined in features.py instead of tests.py):
  • [libc++] Simplify features for detecting atomics' support. llvm/llvm-project#75553
  • [libcxx] Update 128-bit-atomics feature test llvm/llvm-project#83841
• We 'has-no-zdump' (a unix program).
• libcxx now uses 'c++23' instead of 'c++2b'. I believe this was:
  • llvm/llvm-project@71400505ca04
  • [libc++] Remove workaround for clang-tidy 16 in the test suite setup code llvm/llvm-project#69035
• Remove C++26 features from 'MISSING STL FEATURES'.
  • Now that we're identifying ourselves as being a C++23 implementation.
• Update magic comments.
  • These are used by the internal test harness to skip tests.
  • The two removed lines no longer appear in libcxx.
• range_adaptor_closure.pass.cpp needs WG21-P1169R4 static operator().
• Add missing newline.
• Mark vector.modifiers/destroy_elements.pass.cpp as failing due to constexpr step limits.
• Categorize failing tests.
• format.range.formatter/parse.pass.cpp is now passing after Add range_formatter #4642.
• Recategorize format.range.formatter/format.pass.cpp.
• Skip ranges.ends_with.pass.cpp which sporadically fails with "fatal error C1060: compiler is out of heap space".
• Finally, we need to update tests/std/tests/P0088R3_variant/test.cpp because it uses LLVM machinery. Both VariantAllowsNarrowingConversions and variant<T&> coverage were removed:
  • [libc++] Remove _LIBCPP_ENABLE_NARROWING_CONVERSIONS_IN_VARIANT llvm/llvm-project#83928
  • [libc++][test] remove tests that testing std::variant<T&> llvm/llvm-project#84222

I'm working on a full regeneration of P0088R3_variant, but that's going to be a much larger change and I don't want to mix that into this PR.

[MahmoudGSaleh]

LGTM