test: avoid strict-aliasing/alignment UB in unit tests#110
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test: avoid strict-aliasing/alignment UB in unit tests#110
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The unit tests were writing through typed pointers into byte storage: - `cuckoocache_tests.cpp` casted `uint256::begin()` to `uint32_t*` and wrote words. This is strict-aliasing UB (and can be miscompiled under -O2). Replace with `WriteLE32()` stores into the byte buffer. - `allocator_tests.cpp` casted an untyped `void*` allocation to `uint32_t*` and dereferenced it. This can be misaligned access UB on some platforms. Replace with `std::memcpy()` store/load.
Clean up pass-by-const-ref of fundamental types: - `CScriptNum` `int64_t` ctor/operators and `serialize()` now take `int64_t` by value instead of `const int64_t&` (no logic change; avoids unnecessary references in a hot/consensus-adjacent header). - `memusage::DynamicUsage()` overloads for built-in scalars/pointers take values by value (still always returns 0). - `coinselection.cpp` loop index uses `size_t` by value instead of `const size_t&`.
The SHA-NI implementation used `(__m128i*)` casts with `_mm_loadu_si128` and `_mm_storeu_si128`. Switch to `__m128i_u` (with a safe fallback typedef) so unaligned access is explicit and we avoid relying on type-punned SIMD pointer casts for these intrinsics. No intended behavior or performance change.
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WIP