Split migrations folder (#21549)

There are too many files in `models/migrations` folder so that I split
them into sub folders.

models/migrations/v1_8/v76.go

@@ -0,0 +1,75 @@
+// Copyright 2018 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package v1_8 // nolint
+
+import (
+	"fmt"
+
+	"code.gitea.io/gitea/modules/timeutil"
+
+	"xorm.io/xorm"
+)
+
+func AddPullRequestRebaseWithMerge(x *xorm.Engine) error {
+	// RepoUnit describes all units of a repository
+	type RepoUnit struct {
+		ID          int64
+		RepoID      int64                  `xorm:"INDEX(s)"`
+		Type        int                    `xorm:"INDEX(s)"`
+		Config      map[string]interface{} `xorm:"JSON"`
+		CreatedUnix timeutil.TimeStamp     `xorm:"INDEX CREATED"`
+	}
+
+	const (
+		v16UnitTypeCode            = iota + 1 // 1 code
+		v16UnitTypeIssues                     // 2 issues
+		v16UnitTypePRs                        // 3 PRs
+		v16UnitTypeCommits                    // 4 Commits
+		v16UnitTypeReleases                   // 5 Releases
+		v16UnitTypeWiki                       // 6 Wiki
+		v16UnitTypeSettings                   // 7 Settings
+		v16UnitTypeExternalWiki               // 8 ExternalWiki
+		v16UnitTypeExternalTracker            // 9 ExternalTracker
+	)
+
+	sess := x.NewSession()
+	defer sess.Close()
+	if err := sess.Begin(); err != nil {
+		return err
+	}
+
+	// Updating existing issue units
+	units := make([]*RepoUnit, 0, 100)
+	if err := sess.Where("`type` = ?", v16UnitTypePRs).Find(&units); err != nil {
+		return fmt.Errorf("Query repo units: %w", err)
+	}
+	for _, unit := range units {
+		if unit.Config == nil {
+			unit.Config = make(map[string]interface{})
+		}
+		// Allow the new merge style if all other merge styles are allowed
+		allowMergeRebase := true
+
+		if allowMerge, ok := unit.Config["AllowMerge"]; ok {
+			allowMergeRebase = allowMergeRebase && allowMerge.(bool)
+		}
+
+		if allowRebase, ok := unit.Config["AllowRebase"]; ok {
+			allowMergeRebase = allowMergeRebase && allowRebase.(bool)
+		}
+
+		if allowSquash, ok := unit.Config["AllowSquash"]; ok {
+			allowMergeRebase = allowMergeRebase && allowSquash.(bool)
+		}
+
+		if _, ok := unit.Config["AllowRebaseMerge"]; !ok {
+			unit.Config["AllowRebaseMerge"] = allowMergeRebase
+		}
+		if _, err := sess.ID(unit.ID).Cols("config").Update(unit); err != nil {
+			return err
+		}
+	}
+	return sess.Commit()
+}