chore: import upstream snapshot with attribution

cmake/checks/cpu_sve.cpp

@@ -0,0 +1,24 @@
+#include <stdio.h>
+
+#if defined(__ARM_FEATURE_SVE)
+#  include <arm_sve.h>
+#  define CV_SVE 1
+#endif
+
+#if defined(CV_SVE)
+int test()
+{
+    const float src[1024] = {0.0};
+    svbool_t pg = svptrue_b32();
+    svfloat32_t val = svld1(pg, src);
+    return (int)svlastb_f32(pg, val);
+}
+#else
+#error "SVE is not supported"
+#endif
+
+int main()
+{
+  printf("%d\n", test());
+  return 0;
+}