Modules: repair libxml2 link on Windows

Modules/libxml2-markup.h

@@ -10,4 +10,31 @@
 #include <libxml2/libxml/entities.h>
 #include <libxml2/libxml/SAX.h>
 #include <libxml2/libxml/SAX2.h>
+
+#if defined(_WIN32)
+# if defined(LIBXML_STATIC)
+#   if defined(LIBXML_DEBUG)
+#     pragma comment(lib, "libxml2sd.lib")
+#   else
+#     pragma comment(lib, "libxml2s.lib")
+#   endif
+# else
+#   if defined(LIBXML_DEBUG)
+#     pragma comment(lib, "xml2d.lib")
+#   else
+#     pragma comment(lib, "xml2.lib")
+#   endif
+# endif
+#elif defined(__ELF__)
+__asm__ (".section .swift1_autolink_entries,\"a\",@progbits\n"
+         ".p2align 3\n"
+         ".L_swift1_autolink_entries:\n"
+         "  .asciz \"-lxml2\"\n"
+         "  .size .L_swift1_autolink_entries, 7\n");
+#elif defined(__wasm__)
+#warning WASM autolinking not implemented
+#else /* assume MachO */
+__asm__ (".linker_option \"-lxml2\"\n");
+#endif
+
 #endif /* LIBXML2_MARKUP_H */

Modules/module.modulemap

@@ -1,5 +1,4 @@
 module libxml2 [system] {
-    link "xml2"
     umbrella header "libxml2-markup.h"
     export *
     module * { export * }