switch to go vendoring

vendor/github.com/RoaringBitmap/roaring/internal/pools.go

@@ -0,0 +1,21 @@
+package internal
+
+import (
+	"sync"
+)
+
+var (
+	// ByteInputAdapterPool shared pool
+	ByteInputAdapterPool = sync.Pool{
+		New: func() interface{} {
+			return &ByteInputAdapter{}
+		},
+	}
+
+	// ByteBufferPool shared pool
+	ByteBufferPool = sync.Pool{
+		New: func() interface{} {
+			return &ByteBuffer{}
+		},
+	}
+)