0547c41f90
LLVM 18 x86 data layout update With https://reviews.llvm.org/D86310 LLVM now has i128 aligned to 16-bytes on x86 based platforms. This will be in LLVM-18. This patch updates all our spec targets to be 16-byte aligned, and removes the alignment when speaking to older LLVM. This results in Rust overaligning things relative to LLVM on older LLVMs. This implements MCP https://github.com/rust-lang/compiler-team/issues/683. See #54341