diff --git a/vendor/golang.org/x/text/collate/build/colelem.go b/vendor/golang.org/x/text/collate/build/colelem.go
new file mode 100644
index 0000000..04fc3bf
--- /dev/null
+++ b/vendor/golang.org/x/text/collate/build/colelem.go
@@ -0,0 +1,294 @@
+// Copyright 2012 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 build
+
+import (
+	"fmt"
+	"unicode"
+
+	"golang.org/x/text/internal/colltab"
+)
+
+const (
+	defaultSecondary = 0x20
+	defaultTertiary  = 0x2
+	maxTertiary      = 0x1F
+)
+
+type rawCE struct {
+	w   []int
+	ccc uint8
+}
+
+func makeRawCE(w []int, ccc uint8) rawCE {
+	ce := rawCE{w: make([]int, 4), ccc: ccc}
+	copy(ce.w, w)
+	return ce
+}
+
+// A collation element is represented as an uint32.
+// In the typical case, a rune maps to a single collation element. If a rune
+// can be the start of a contraction or expands into multiple collation elements,
+// then the collation element that is associated with a rune will have a special
+// form to represent such m to n mappings.  Such special collation elements
+// have a value >= 0x80000000.
+
+const (
+	maxPrimaryBits   = 21
+	maxSecondaryBits = 12
+	maxTertiaryBits  = 8
+)
+
+func makeCE(ce rawCE) (uint32, error) {
+	v, e := colltab.MakeElem(ce.w[0], ce.w[1], ce.w[2], ce.ccc)
+	return uint32(v), e
+}
+
+// For contractions, collation elements are of the form
+// 110bbbbb bbbbbbbb iiiiiiii iiiinnnn, where
+//   - n* is the size of the first node in the contraction trie.
+//   - i* is the index of the first node in the contraction trie.
+//   - b* is the offset into the contraction collation element table.
+// See contract.go for details on the contraction trie.
+const (
+	contractID            = 0xC0000000
+	maxNBits              = 4
+	maxTrieIndexBits      = 12
+	maxContractOffsetBits = 13
+)
+
+func makeContractIndex(h ctHandle, offset int) (uint32, error) {
+	if h.n >= 1<<maxNBits {
+		return 0, fmt.Errorf("size of contraction trie node too large: %d >= %d", h.n, 1<<maxNBits)
+	}
+	if h.index >= 1<<maxTrieIndexBits {
+		return 0, fmt.Errorf("size of contraction trie offset too large: %d >= %d", h.index, 1<<maxTrieIndexBits)
+	}
+	if offset >= 1<<maxContractOffsetBits {
+		return 0, fmt.Errorf("contraction offset out of bounds: %x >= %x", offset, 1<<maxContractOffsetBits)
+	}
+	ce := uint32(contractID)
+	ce += uint32(offset << (maxNBits + maxTrieIndexBits))
+	ce += uint32(h.index << maxNBits)
+	ce += uint32(h.n)
+	return ce, nil
+}
+
+// For expansions, collation elements are of the form
+// 11100000 00000000 bbbbbbbb bbbbbbbb,
+// where b* is the index into the expansion sequence table.
+const (
+	expandID           = 0xE0000000
+	maxExpandIndexBits = 16
+)
+
+func makeExpandIndex(index int) (uint32, error) {
+	if index >= 1<<maxExpandIndexBits {
+		return 0, fmt.Errorf("expansion index out of bounds: %x >= %x", index, 1<<maxExpandIndexBits)
+	}
+	return expandID + uint32(index), nil
+}
+
+// Each list of collation elements corresponding to an expansion starts with
+// a header indicating the length of the sequence.
+func makeExpansionHeader(n int) (uint32, error) {
+	return uint32(n), nil
+}
+
+// Some runes can be expanded using NFKD decomposition. Instead of storing the full
+// sequence of collation elements, we decompose the rune and lookup the collation
+// elements for each rune in the decomposition and modify the tertiary weights.
+// The collation element, in this case, is of the form
+// 11110000 00000000 wwwwwwww vvvvvvvv, where
+//   - v* is the replacement tertiary weight for the first rune,
+//   - w* is the replacement tertiary weight for the second rune,
+// Tertiary weights of subsequent runes should be replaced with maxTertiary.
+// See https://www.unicode.org/reports/tr10/#Compatibility_Decompositions for more details.
+const (
+	decompID = 0xF0000000
+)
+
+func makeDecompose(t1, t2 int) (uint32, error) {
+	if t1 >= 256 || t1 < 0 {
+		return 0, fmt.Errorf("first tertiary weight out of bounds: %d >= 256", t1)
+	}
+	if t2 >= 256 || t2 < 0 {
+		return 0, fmt.Errorf("second tertiary weight out of bounds: %d >= 256", t2)
+	}
+	return uint32(t2<<8+t1) + decompID, nil
+}
+
+const (
+	// These constants were taken from https://www.unicode.org/versions/Unicode6.0.0/ch12.pdf.
+	minUnified       rune = 0x4E00
+	maxUnified            = 0x9FFF
+	minCompatibility      = 0xF900
+	maxCompatibility      = 0xFAFF
+	minRare               = 0x3400
+	maxRare               = 0x4DBF
+)
+const (
+	commonUnifiedOffset = 0x10000
+	rareUnifiedOffset   = 0x20000 // largest rune in common is U+FAFF
+	otherOffset         = 0x50000 // largest rune in rare is U+2FA1D
+	illegalOffset       = otherOffset + int(unicode.MaxRune)
+	maxPrimary          = illegalOffset + 1
+)
+
+// implicitPrimary returns the primary weight for the a rune
+// for which there is no entry for the rune in the collation table.
+// We take a different approach from the one specified in
+// https://unicode.org/reports/tr10/#Implicit_Weights,
+// but preserve the resulting relative ordering of the runes.
+func implicitPrimary(r rune) int {
+	if unicode.Is(unicode.Ideographic, r) {
+		if r >= minUnified && r <= maxUnified {
+			// The most common case for CJK.
+			return int(r) + commonUnifiedOffset
+		}
+		if r >= minCompatibility && r <= maxCompatibility {
+			// This will typically not hit. The DUCET explicitly specifies mappings
+			// for all characters that do not decompose.
+			return int(r) + commonUnifiedOffset
+		}
+		return int(r) + rareUnifiedOffset
+	}
+	return int(r) + otherOffset
+}
+
+// convertLargeWeights converts collation elements with large
+// primaries (either double primaries or for illegal runes)
+// to our own representation.
+// A CJK character C is represented in the DUCET as
+//   [.FBxx.0020.0002.C][.BBBB.0000.0000.C]
+// We will rewrite these characters to a single CE.
+// We assume the CJK values start at 0x8000.
+// See https://unicode.org/reports/tr10/#Implicit_Weights
+func convertLargeWeights(elems []rawCE) (res []rawCE, err error) {
+	const (
+		cjkPrimaryStart   = 0xFB40
+		rarePrimaryStart  = 0xFB80
+		otherPrimaryStart = 0xFBC0
+		illegalPrimary    = 0xFFFE
+		highBitsMask      = 0x3F
+		lowBitsMask       = 0x7FFF
+		lowBitsFlag       = 0x8000
+		shiftBits         = 15
+	)
+	for i := 0; i < len(elems); i++ {
+		ce := elems[i].w
+		p := ce[0]
+		if p < cjkPrimaryStart {
+			continue
+		}
+		if p > 0xFFFF {
+			return elems, fmt.Errorf("found primary weight %X; should be <= 0xFFFF", p)
+		}
+		if p >= illegalPrimary {
+			ce[0] = illegalOffset + p - illegalPrimary
+		} else {
+			if i+1 >= len(elems) {
+				return elems, fmt.Errorf("second part of double primary weight missing: %v", elems)
+			}
+			if elems[i+1].w[0]&lowBitsFlag == 0 {
+				return elems, fmt.Errorf("malformed second part of double primary weight: %v", elems)
+			}
+			np := ((p & highBitsMask) << shiftBits) + elems[i+1].w[0]&lowBitsMask
+			switch {
+			case p < rarePrimaryStart:
+				np += commonUnifiedOffset
+			case p < otherPrimaryStart:
+				np += rareUnifiedOffset
+			default:
+				p += otherOffset
+			}
+			ce[0] = np
+			for j := i + 1; j+1 < len(elems); j++ {
+				elems[j] = elems[j+1]
+			}
+			elems = elems[:len(elems)-1]
+		}
+	}
+	return elems, nil
+}
+
+// nextWeight computes the first possible collation weights following elems
+// for the given level.
+func nextWeight(level colltab.Level, elems []rawCE) []rawCE {
+	if level == colltab.Identity {
+		next := make([]rawCE, len(elems))
+		copy(next, elems)
+		return next
+	}
+	next := []rawCE{makeRawCE(elems[0].w, elems[0].ccc)}
+	next[0].w[level]++
+	if level < colltab.Secondary {
+		next[0].w[colltab.Secondary] = defaultSecondary
+	}
+	if level < colltab.Tertiary {
+		next[0].w[colltab.Tertiary] = defaultTertiary
+	}
+	// Filter entries that cannot influence ordering.
+	for _, ce := range elems[1:] {
+		skip := true
+		for i := colltab.Primary; i < level; i++ {
+			skip = skip && ce.w[i] == 0
+		}
+		if !skip {
+			next = append(next, ce)
+		}
+	}
+	return next
+}
+
+func nextVal(elems []rawCE, i int, level colltab.Level) (index, value int) {
+	for ; i < len(elems) && elems[i].w[level] == 0; i++ {
+	}
+	if i < len(elems) {
+		return i, elems[i].w[level]
+	}
+	return i, 0
+}
+
+// compareWeights returns -1 if a < b, 1 if a > b, or 0 otherwise.
+// It also returns the collation level at which the difference is found.
+func compareWeights(a, b []rawCE) (result int, level colltab.Level) {
+	for level := colltab.Primary; level < colltab.Identity; level++ {
+		var va, vb int
+		for ia, ib := 0, 0; ia < len(a) || ib < len(b); ia, ib = ia+1, ib+1 {
+			ia, va = nextVal(a, ia, level)
+			ib, vb = nextVal(b, ib, level)
+			if va != vb {
+				if va < vb {
+					return -1, level
+				} else {
+					return 1, level
+				}
+			}
+		}
+	}
+	return 0, colltab.Identity
+}
+
+func equalCE(a, b rawCE) bool {
+	for i := 0; i < 3; i++ {
+		if b.w[i] != a.w[i] {
+			return false
+		}
+	}
+	return true
+}
+
+func equalCEArrays(a, b []rawCE) bool {
+	if len(a) != len(b) {
+		return false
+	}
+	for i := range a {
+		if !equalCE(a[i], b[i]) {
+			return false
+		}
+	}
+	return true
+}