Initial QSfera import

Server/vendor/github.com/RoaringBitmap/roaring/v2/ctz.go

@@ -0,0 +1,21 @@
+//go:build go1.9
+// +build go1.9
+
+// "go1.9", from Go version 1.9 onward
+// See https://golang.org/pkg/go/build/#hdr-Build_Constraints
+
+package roaring
+
+import "math/bits"
+
+// countTrailingZeros returns the number of trailing zero bits in x; the result is 64 for x == 0.
+func countTrailingZeros(x uint64) int {
+	return bits.TrailingZeros64(x)
+}
+
+// countTrailingOnes returns the number of trailing one bits in x
+// The result is 64 for x == 9,223,372,036,854,775,807.
+// The result is 0 for x == 0.
+func countTrailingOnes(x uint64) int {
+	return bits.TrailingZeros64(^x)
+}