migrate go version to 1.17 (#203)

* migrate go version to 1.17

* update contributing

vendor/github.com/goccy/go-json/internal/decoder/anonymous_field.go

@@ -0,0 +1,37 @@
+package decoder
+
+import (
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+type anonymousFieldDecoder struct {
+	structType *runtime.Type
+	offset     uintptr
+	dec        Decoder
+}
+
+func newAnonymousFieldDecoder(structType *runtime.Type, offset uintptr, dec Decoder) *anonymousFieldDecoder {
+	return &anonymousFieldDecoder{
+		structType: structType,
+		offset:     offset,
+		dec:        dec,
+	}
+}
+
+func (d *anonymousFieldDecoder) DecodeStream(s *Stream, depth int64, p unsafe.Pointer) error {
+	if *(*unsafe.Pointer)(p) == nil {
+		*(*unsafe.Pointer)(p) = unsafe_New(d.structType)
+	}
+	p = *(*unsafe.Pointer)(p)
+	return d.dec.DecodeStream(s, depth, unsafe.Pointer(uintptr(p)+d.offset))
+}
+
+func (d *anonymousFieldDecoder) Decode(ctx *RuntimeContext, cursor, depth int64, p unsafe.Pointer) (int64, error) {
+	if *(*unsafe.Pointer)(p) == nil {
+		*(*unsafe.Pointer)(p) = unsafe_New(d.structType)
+	}
+	p = *(*unsafe.Pointer)(p)
+	return d.dec.Decode(ctx, cursor, depth, unsafe.Pointer(uintptr(p)+d.offset))
+}