Fix T68944: Added check for SSE4.1 to denoising node.

Since OpenImageDenoise requires a CPU with SSE 4.1 or newer,
let the node act as passthrough on unsupported CPUs and display
a message in the node itself.

source/blender/blenlib/BLI_system.h

@@ -24,6 +24,7 @@
  */
 
 int BLI_cpu_support_sse2(void);
+int BLI_cpu_support_sse41(void);
 void BLI_system_backtrace(FILE *fp);
 
 /* Get CPU brand, result is to be MEM_freeN()-ed. */

source/blender/blenlib/intern/system.c

@@ -179,6 +179,19 @@ char *BLI_cpu_brand_string(void)
   return NULL;
 }
 
+int BLI_cpu_support_sse41(void)
+{
+  int result[4], num;
+  __cpuid(result, 0);
+  num = result[0];
+
+  if (num >= 1) {
+    __cpuid(result, 0x00000001);
+    return (result[2] & ((int)1 << 19)) != 0;
+  }
+  return 0;
+}
+
 void BLI_hostname_get(char *buffer, size_t bufsize)
 {
 #ifndef WIN32