* ConflictSet.cpp: enable the interleaved read/write path whenever
musttail is available, falling back to the default calling convention
when preserve_none is not supported. This prevents a large block of
compiled-but-dead code from being counted in coverage.
* CMakeLists.txt: detect which arch-specific hardening-check options the
installed hardening-check binary supports, including the newer
hyphenated spellings, so the release test no longer fails with an
unknown option.
* .gitea/workflows/ci.yml: build the coverage job with
-DUSE_SIMD_FALLBACK=ON so AVX512-only functions that cannot execute on
the CI runners are not counted against line coverage.
`ConflictSet(const ConflictSet&)` and `operator=(const ConflictSet&)` were
only deleted for C++11 and later. In C++98/C++03 the compiler implicitly
generated public copy operations, so copying a ConflictSet shared the opaque
`Impl*` and caused a double-free on destruction.
Declare both operations private and leave them undefined when
`__cplusplus <= 199711L`, matching the standard pre-C++11 idiom for
move-only types. Guard the declarations with `defined(__cplusplus)` so
they are not exposed to C90 compilation units.
Closes#48
weaselbot
