Report SkylakeX as Haswell if compiler does not support AVX512

... or make was invoked with NO_AVX512=1

getarch.c

@@ -91,6 +91,10 @@ USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <unistd.h>
 #endif
 
+#if (( defined(__GNUC__)  && __GNUC__   > 6 && defined(__AVX2__)) || (defined(__clang__) && __clang_major__ >= 6))
+#else
+#define NO_AVX512
+#endif
 /* #define FORCE_P2		*/
 /* #define FORCE_KATMAI		*/
 /* #define FORCE_COPPERMINE	*/
@@ -327,6 +331,20 @@ USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #endif
 
 #ifdef FORCE_SKYLAKEX
+#ifdef NO_AVX512
+#define FORCE
+#define FORCE_INTEL
+#define ARCHITECTURE    "X86"
+#define SUBARCHITECTURE "HASWELL"
+#define ARCHCONFIG   "-DHASWELL " \
+		     "-DL1_DATA_SIZE=32768 -DL1_DATA_LINESIZE=64 " \
+		     "-DL2_SIZE=262144 -DL2_LINESIZE=64 " \
+		     "-DDTB_DEFAULT_ENTRIES=64 -DDTB_SIZE=4096 " \
+		     "-DHAVE_CMOV -DHAVE_MMX -DHAVE_SSE -DHAVE_SSE2 -DHAVE_SSE3 -DHAVE_SSSE3 -DHAVE_SSE4_1 -DHAVE_SSE4_2 -DHAVE_AVX " \
+                     "-DFMA3"
+#define LIBNAME   "haswell"
+#define CORENAME  "HASWELL"
+#else
 #define FORCE
 #define FORCE_INTEL
 #define ARCHITECTURE    "X86"
@@ -340,6 +358,7 @@ USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #define LIBNAME   "skylakex"
 #define CORENAME  "SKYLAKEX"
 #endif
+#endif
 
 #ifdef FORCE_ATOM
 #define FORCE