Enable AMD64 arcfour implementation on WIN64
* cipher/arcfour-amd64.S: Enable when HAVE_COMPATIBLE_GCC_WIN64_PLATFORM_AS defined. (ELF): New macro to mask lines with ELF specific commands. * cipher/arcfour.c (USE_AMD64_ASM): Enable when HAVE_COMPATIBLE_GCC_WIN64_PLATFORM_AS defined. (do_encrypt, do_decrypt) [HAVE_COMPATIBLE_GCC_WIN64_PLATFORM_AS]: Use assembly block to call AMD64 assembly function.
- Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>