migrate go version to 1.17 (#203)

* migrate go version to 1.17

* update contributing

vendor/github.com/goccy/go-json/decode_ptr.go

@@ -1,85 +0,0 @@
-package json
-
-import (
-	"unsafe"
-)
-
-type ptrDecoder struct {
-	dec        decoder
-	typ        *rtype
-	structName string
-	fieldName  string
-}
-
-func newPtrDecoder(dec decoder, typ *rtype, structName, fieldName string) *ptrDecoder {
-	return &ptrDecoder{
-		dec:        dec,
-		typ:        typ,
-		structName: structName,
-		fieldName:  fieldName,
-	}
-}
-
-func (d *ptrDecoder) contentDecoder() decoder {
-	dec, ok := d.dec.(*ptrDecoder)
-	if !ok {
-		return d.dec
-	}
-	return dec.contentDecoder()
-}
-
-//nolint:golint
-//go:linkname unsafe_New reflect.unsafe_New
-func unsafe_New(*rtype) unsafe.Pointer
-
-func (d *ptrDecoder) decodeStream(s *stream, depth int64, p unsafe.Pointer) error {
-	s.skipWhiteSpace()
-	if s.char() == nul {
-		s.read()
-	}
-	if s.char() == 'n' {
-		if err := nullBytes(s); err != nil {
-			return err
-		}
-		*(*unsafe.Pointer)(p) = nil
-		return nil
-	}
-	var newptr unsafe.Pointer
-	if *(*unsafe.Pointer)(p) == nil {
-		newptr = unsafe_New(d.typ)
-		*(*unsafe.Pointer)(p) = newptr
-	} else {
-		newptr = *(*unsafe.Pointer)(p)
-	}
-	if err := d.dec.decodeStream(s, depth, newptr); err != nil {
-		return err
-	}
-	return nil
-}
-
-func (d *ptrDecoder) decode(buf []byte, cursor, depth int64, p unsafe.Pointer) (int64, error) {
-	cursor = skipWhiteSpace(buf, cursor)
-	if buf[cursor] == 'n' {
-		if err := validateNull(buf, cursor); err != nil {
-			return 0, err
-		}
-		if p != nil {
-			*(*unsafe.Pointer)(p) = nil
-		}
-		cursor += 4
-		return cursor, nil
-	}
-	var newptr unsafe.Pointer
-	if *(*unsafe.Pointer)(p) == nil {
-		newptr = unsafe_New(d.typ)
-		*(*unsafe.Pointer)(p) = newptr
-	} else {
-		newptr = *(*unsafe.Pointer)(p)
-	}
-	c, err := d.dec.decode(buf, cursor, depth, newptr)
-	if err != nil {
-		return 0, err
-	}
-	cursor = c
-	return cursor, nil
-}