Update vendored libs

vendor/github.com/klauspost/compress/zstd/zstd.go

@@ -9,6 +9,7 @@ import (
 	"errors"
 	"log"
 	"math"
+	"math/bits"
 )
 
 // enable debug printing
@@ -105,12 +106,33 @@ func printf(format string, a ...interface{}) {
 	}
 }
 
+// matchLen returns the maximum common prefix length of a and b.
+// a must be the shortest of the two.
+func matchLen(a, b []byte) (n int) {
+	for ; len(a) >= 8 && len(b) >= 8; a, b = a[8:], b[8:] {
+		diff := binary.LittleEndian.Uint64(a) ^ binary.LittleEndian.Uint64(b)
+		if diff != 0 {
+			return n + bits.TrailingZeros64(diff)>>3
+		}
+		n += 8
+	}
+
+	for i := range a {
+		if a[i] != b[i] {
+			break
+		}
+		n++
+	}
+	return n
+
+}
+
 func load3232(b []byte, i int32) uint32 {
-	return binary.LittleEndian.Uint32(b[:len(b):len(b)][i:])
+	return binary.LittleEndian.Uint32(b[i:])
 }
 
 func load6432(b []byte, i int32) uint64 {
-	return binary.LittleEndian.Uint64(b[:len(b):len(b)][i:])
+	return binary.LittleEndian.Uint64(b[i:])
 }
 
 type byter interface {