Revert vendor directory to support old golang (GOPATH mode)

gomodule is still in progress to migrate for now, hence multus
team decide to keep vendor directory to support build without
gomodule.

vendor/github.com/modern-go/reflect2/reflect2_kind.go

@@ -0,0 +1,30 @@
+package reflect2
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+// DefaultTypeOfKind return the non aliased default type for the kind
+func DefaultTypeOfKind(kind reflect.Kind) Type {
+	return kindTypes[kind]
+}
+
+var kindTypes = map[reflect.Kind]Type{
+	reflect.Bool:          TypeOf(true),
+	reflect.Uint8:         TypeOf(uint8(0)),
+	reflect.Int8:          TypeOf(int8(0)),
+	reflect.Uint16:        TypeOf(uint16(0)),
+	reflect.Int16:         TypeOf(int16(0)),
+	reflect.Uint32:        TypeOf(uint32(0)),
+	reflect.Int32:         TypeOf(int32(0)),
+	reflect.Uint64:        TypeOf(uint64(0)),
+	reflect.Int64:         TypeOf(int64(0)),
+	reflect.Uint:          TypeOf(uint(0)),
+	reflect.Int:           TypeOf(int(0)),
+	reflect.Float32:       TypeOf(float32(0)),
+	reflect.Float64:       TypeOf(float64(0)),
+	reflect.Uintptr:       TypeOf(uintptr(0)),
+	reflect.String:        TypeOf(""),
+	reflect.UnsafePointer: TypeOf(unsafe.Pointer(nil)),
+}