Use mod vendor for vendored directory (backwards compatible)

vendor/golang.org/x/text/internal/language/coverage.go

@@ -1,28 +0,0 @@
-// Copyright 2014 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package language
-
-// BaseLanguages returns the list of all supported base languages. It generates
-// the list by traversing the internal structures.
-func BaseLanguages() []Language {
-	base := make([]Language, 0, NumLanguages)
-	for i := 0; i < langNoIndexOffset; i++ {
-		// We included "und" already for the value 0.
-		if i != nonCanonicalUnd {
-			base = append(base, Language(i))
-		}
-	}
-	i := langNoIndexOffset
-	for _, v := range langNoIndex {
-		for k := 0; k < 8; k++ {
-			if v&1 == 1 {
-				base = append(base, Language(i))
-			}
-			v >>= 1
-			i++
-		}
-	}
-	return base
-}