diff --git a/vendor/golang.org/x/text/unicode/bidi/gen.go b/vendor/golang.org/x/text/unicode/bidi/gen.go
new file mode 100644
index 0000000..987fc16
--- /dev/null
+++ b/vendor/golang.org/x/text/unicode/bidi/gen.go
@@ -0,0 +1,133 @@
+// Copyright 2015 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.
+
+// +build ignore
+
+package main
+
+import (
+	"flag"
+	"log"
+
+	"golang.org/x/text/internal/gen"
+	"golang.org/x/text/internal/triegen"
+	"golang.org/x/text/internal/ucd"
+)
+
+var outputFile = flag.String("out", "tables.go", "output file")
+
+func main() {
+	gen.Init()
+	gen.Repackage("gen_trieval.go", "trieval.go", "bidi")
+	gen.Repackage("gen_ranges.go", "ranges_test.go", "bidi")
+
+	genTables()
+}
+
+// bidiClass names and codes taken from class "bc" in
+// https://www.unicode.org/Public/8.0.0/ucd/PropertyValueAliases.txt
+var bidiClass = map[string]Class{
+	"AL":  AL,  // ArabicLetter
+	"AN":  AN,  // ArabicNumber
+	"B":   B,   // ParagraphSeparator
+	"BN":  BN,  // BoundaryNeutral
+	"CS":  CS,  // CommonSeparator
+	"EN":  EN,  // EuropeanNumber
+	"ES":  ES,  // EuropeanSeparator
+	"ET":  ET,  // EuropeanTerminator
+	"L":   L,   // LeftToRight
+	"NSM": NSM, // NonspacingMark
+	"ON":  ON,  // OtherNeutral
+	"R":   R,   // RightToLeft
+	"S":   S,   // SegmentSeparator
+	"WS":  WS,  // WhiteSpace
+
+	"FSI": Control,
+	"PDF": Control,
+	"PDI": Control,
+	"LRE": Control,
+	"LRI": Control,
+	"LRO": Control,
+	"RLE": Control,
+	"RLI": Control,
+	"RLO": Control,
+}
+
+func genTables() {
+	if numClass > 0x0F {
+		log.Fatalf("Too many Class constants (%#x > 0x0F).", numClass)
+	}
+	w := gen.NewCodeWriter()
+	defer w.WriteVersionedGoFile(*outputFile, "bidi")
+
+	gen.WriteUnicodeVersion(w)
+
+	t := triegen.NewTrie("bidi")
+
+	// Build data about bracket mapping. These bits need to be or-ed with
+	// any other bits.
+	orMask := map[rune]uint64{}
+
+	xorMap := map[rune]int{}
+	xorMasks := []rune{0} // First value is no-op.
+
+	ucd.Parse(gen.OpenUCDFile("BidiBrackets.txt"), func(p *ucd.Parser) {
+		r1 := p.Rune(0)
+		r2 := p.Rune(1)
+		xor := r1 ^ r2
+		if _, ok := xorMap[xor]; !ok {
+			xorMap[xor] = len(xorMasks)
+			xorMasks = append(xorMasks, xor)
+		}
+		entry := uint64(xorMap[xor]) << xorMaskShift
+		switch p.String(2) {
+		case "o":
+			entry |= openMask
+		case "c", "n":
+		default:
+			log.Fatalf("Unknown bracket class %q.", p.String(2))
+		}
+		orMask[r1] = entry
+	})
+
+	w.WriteComment(`
+	xorMasks contains masks to be xor-ed with brackets to get the reverse
+	version.`)
+	w.WriteVar("xorMasks", xorMasks)
+
+	done := map[rune]bool{}
+
+	insert := func(r rune, c Class) {
+		if !done[r] {
+			t.Insert(r, orMask[r]|uint64(c))
+			done[r] = true
+		}
+	}
+
+	// Insert the derived BiDi properties.
+	ucd.Parse(gen.OpenUCDFile("extracted/DerivedBidiClass.txt"), func(p *ucd.Parser) {
+		r := p.Rune(0)
+		class, ok := bidiClass[p.String(1)]
+		if !ok {
+			log.Fatalf("%U: Unknown BiDi class %q", r, p.String(1))
+		}
+		insert(r, class)
+	})
+	visitDefaults(insert)
+
+	// TODO: use sparse blocks. This would reduce table size considerably
+	// from the looks of it.
+
+	sz, err := t.Gen(w)
+	if err != nil {
+		log.Fatal(err)
+	}
+	w.Size += sz
+}
+
+// dummy values to make methods in gen_common compile. The real versions
+// will be generated by this file to tables.go.
+var (
+	xorMasks []rune
+)