Fix Windows FFI build and missing test imports

Message

Guard Unix-only dlopen helpers (trydlopen, trylinkerscript, searchlibrarypath) with #ifndef WIN32 so the Windows cross-compile via Zig doesn't see undeclared dlopen/RTLDNOW. The main platform dispatch in ffiopen_library was already guarded.

Add missing (sigil fs) import to cairo, harfbuzz, and freetype tests that use file-exists? — caused unbound variable error in CI.

Changed

 native/ffi.c | 2 ++
 1 file changed, 2 insertions(+)

Diff

native/ffi.cmodified

@@ -299,6 +299,7 @@ static char *extract_cstring(Value v)

299

* Platform Abstraction: dlopen/dlsym

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* ============================================================ */

301

+302

#ifndef _WIN32

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/* Try dlopen with a specific path */

304

static void *try_dlopen(const char *path)

305

{

@@ -396,6 +397,7 @@ static void *search_library_path(const char *name)

397

}

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return NULL;

399

}

+400

#endif /* !_WIN32 */

401

402

static void *ffi_open_library(const char *name)

403

{