Clang's PS4 and PS5 targets set the default new alignment and the suitable
alignment to 32 bytes, so PS5 code may store to a fresh mspace block with
32-byte-aligned AVX instructions, as the guest heap already allows since
#1621. The mspace allocator aligned blocks to 16 bytes only. Every mspace
allocation is now aligned to at least 32 bytes.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>