Generate and link native Windows MSVC programs for amd64 and ARM64

Native Windows ARM64 builds use Rust's MSVC toolchain, but Wave only registers Windows GNU output targets. `host_target_triple()` in `src/cli.rs` always selects `pc-windows-gnu` on Windows; CI explicitly expects that result. Building the compiler with MSVC therefore does not yet provide MSVC-generated Wave executables.

Add `x86_64-pc-windows-msvc` and `aarch64-pc-windows-msvc` target handling, MSVC-compatible object/C ABI verification against clang-cl, and a COFF linker path using link.exe/lld-link with correctly selected Windows SDK/UCRT/VCRuntime libraries. Validate machine type for every library and input. Cover executable startup, DLL exports/imports, aggregate returns, stack arguments, variadic calls, and large stack frames. Missing SDK tools must produce actionable diagnostics.

Rollout: explicit MSVC output first, native executable CI on both architectures next, then change native defaults only after coverage passes. Retain current Windows GNU targets, their linker behavior and CI throughout this work; removing GNU is not authorized in this patch.

Parent/native compiler host builds: #292. Existing native ARM64 execution crash: #493; missing HOME: #492. These are dependencies, not duplicates of this output-target task.

Microsoft ARM64 ABI: https://learn.microsoft.com/en-us/cpp/build/arm64-windows-abi-conventions

Start in src/cli.rs at host_target_triple() and trace the existing Windows GNU target and linker paths, then inspect the Windows CI expectations. Use the stated ABI and toolchain requirements to map coverage for both architectures. Done means explicit MSVC outputs work with validated COFF inputs, startup and ABI cases pass, missing SDK tools give actionable diagnostics, and existing GNU targets and CI remain intact.

Written by the indexing model from the issue text.