fix: fix bug for check unsafe.Pointer isNil (#1319)

Author: sunpe

assert/assertions.go

@@ -530,7 +530,7 @@ func isNil(object interface{}) bool {
 		[]reflect.Kind{
 			reflect.Chan, reflect.Func,
 			reflect.Interface, reflect.Map,
-			reflect.Ptr, reflect.Slice},
+			reflect.Ptr, reflect.Slice, reflect.UnsafePointer},
 		kind)
 
 	if isNilableKind && value.IsNil() {

assert/assertions_test.go

@@ -15,6 +15,7 @@ import (
 	"strings"
 	"testing"
 	"time"
+	"unsafe"
 )
 
 var (
@@ -2558,3 +2559,10 @@ func TestErrorAs(t *testing.T) {
 		})
 	}
 }
+
+func TestIsNil(t *testing.T) {
+	var n unsafe.Pointer = nil
+	if !isNil(n) {
+		t.Fatal("fail")
+	}
+}