x86: Detect feature flags "AVX512DQ", "AVX512IFMA", "AVX512BW", "AVX512VBMI"

Documented in Intel Architecture Set Extensions Programming Reference
(319433-023).

Sponsored by:	EMC / Isilon Storage Division

sys/x86/x86/identcpu.c

@@ -910,12 +910,14 @@ printcpuinfo(void)
 				       "\017MPX"
 				       /* AVX512 Foundation */
 				       "\021AVX512F"
+				       "\022AVX512DQ"
 				       /* Enhanced NRBG */
 				       "\023RDSEED"
 				       /* ADCX + ADOX */
 				       "\024ADX"
 				       /* Supervisor Mode Access Prevention */
 				       "\025SMAP"
+				       "\026AVX512IFMA"
 				       "\027PCOMMIT"
 				       "\030CLFLUSHOPT"
 				       "\031CLWB"
@@ -924,6 +926,7 @@ printcpuinfo(void)
 				       "\034AVX512ER"
 				       "\035AVX512CD"
 				       "\036SHA"
+				       "\037AVX512BW"
 				       );
 			}
 
@@ -932,6 +935,7 @@ printcpuinfo(void)
 				    cpu_stdext_feature2,
 				       "\020"
 				       "\001PREFETCHWT1"
+				       "\002AVX512VBMI"
 				       "\004PKU"
 				       "\005OSPKE"
 				       );