Use goreleaser to build and release (#244)

Instead of using gox on one side and an action to release, we can merge
them together with goreleaser which will build for extra targets (arm,
mips if needed in the future) and it also takes care of creating
checksums, a source archive, and a changelog and creating a release with
all the artifacts.

All binaries should respect the old naming convention, so any scripts
out there should still work.

Signed-off-by: Itxaka <igarcia@suse.com>

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

@@ -5,6 +5,7 @@
 package zstd
 
 import (
+	"encoding/binary"
 	"fmt"
 	"io"
 	"math"
@@ -16,7 +17,7 @@ type frameHeader struct {
 	WindowSize    uint32
 	SingleSegment bool
 	Checksum      bool
-	DictID        uint32 // Not stored.
+	DictID        uint32
 }
 
 const maxHeaderSize = 14
@@ -30,6 +31,24 @@ func (f frameHeader) appendTo(dst []byte) ([]byte, error) {
 	if f.SingleSegment {
 		fhd |= 1 << 5
 	}
+
+	var dictIDContent []byte
+	if f.DictID > 0 {
+		var tmp [4]byte
+		if f.DictID < 256 {
+			fhd |= 1
+			tmp[0] = uint8(f.DictID)
+			dictIDContent = tmp[:1]
+		} else if f.DictID < 1<<16 {
+			fhd |= 2
+			binary.LittleEndian.PutUint16(tmp[:2], uint16(f.DictID))
+			dictIDContent = tmp[:2]
+		} else {
+			fhd |= 3
+			binary.LittleEndian.PutUint32(tmp[:4], f.DictID)
+			dictIDContent = tmp[:4]
+		}
+	}
 	var fcs uint8
 	if f.ContentSize >= 256 {
 		fcs++
@@ -40,6 +59,7 @@ func (f frameHeader) appendTo(dst []byte) ([]byte, error) {
 	if f.ContentSize >= 0xffffffff {
 		fcs++
 	}
+
 	fhd |= fcs << 6
 
 	dst = append(dst, fhd)
@@ -48,7 +68,9 @@ func (f frameHeader) appendTo(dst []byte) ([]byte, error) {
 		windowLog := (bits.Len32(f.WindowSize-1) - winLogMin) << 3
 		dst = append(dst, uint8(windowLog))
 	}
-
+	if f.DictID > 0 {
+		dst = append(dst, dictIDContent...)
+	}
 	switch fcs {
 	case 0:
 		if f.SingleSegment {