Drive a bundled `zig` as `zig cc` for the AOT link step, supplying lld + CRT
+ libc (musl/glibc/mingw) so `sx build` produces native binaries with no host
toolchain. Default Linux output is static musl (portable-anywhere).
- src/zig_backend.zig: discover zig ($SX_ZIG / bundled-next-to-exe / PATH);
bundled-vs-PATH provenance gates auto-activation.
- src/target.zig: selectZigLinker + emitZigLinkArgv + zigTargetTriple, dispatched
before the per-OS branches; macOS/Linux/Windows in scope.
- src/ir/emit_llvm.zig: LLVMNormalizeTargetTriple so vendor-less zig triples
(e.g. x86_64-windows-gnu) parse to the correct OS/object format (COFF not ELF).
- src/main.zig: --self-contained / --no-self-contained; linux-musl, linux-musl-arm,
windows-gnu shorthands; de-vendor linux/linux-arm to match the corpus runner.
- examples/1660: Windows Win32 print-42 + exit(0) via kernel32 (ir-only off-Windows).
Auto-activates only for a bundled zig; a PATH-only zig engages under
--self-contained, so native dev/CI builds are never silently rerouted.
Docs: readme Cross-Compilation, design/bundled-zig-link-backend-design.md, current/PLAN-DIST.md.
