* spu/jsre.h: JSRE_LINK, JSRE_SYMLINK and JSRE_READLINK.
* spu/link.c: New file to add link support via an assist call.
* spu/readlink.c: New file to add readlink support via an assist call.
* spu/symlink.c: New file to add symlink support via an assist call.
* spu/Makefile.in: Add new files.