[regexp] Update RegExp property sequence data to Unicode 12

Unicode v12 was released today:
https://unicode.org/versions/Unicode12.0.0/

This patch updates the following sequence property escapes per
Unicode 12:

- Emoji_Flag_Sequence (no changes)
- Emoji_Keycap_Sequence (no changes)
- Emoji_Tag_Sequence (no changes)
- Emoji_ZWJ_Sequence

Note that Emoji_Modifier_Sequence is still using Unicode 11 data. This
will be fixed automatically once a version of ICU with Unicode 12 support
rolls into V8, at which point I'll update the relevant tests.

Bug: v8:7467
Change-Id: Iba575a471382ba7b029da06c2868c368ff43c649
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1503764Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Mathias Bynens <mathias@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60052}

src/regexp/property-sequences.h

@@ -15,7 +15,6 @@ namespace internal {
 class UnicodePropertySequences : public AllStatic {
  public:
   static const uc32 kEmojiFlagSequences[];
-
   static const uc32 kEmojiTagSequences[];
   static const uc32 kEmojiZWJSequences[];
 };

test/mjsunit/harmony/regexp-property-emoji-flag-sequence-generated.js

-// Copyright 2018 the V8 project authors. All rights reserved.
+// Copyright 2019 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Flags: --harmony-regexp-sequence
 
+// These tests have been generated by the script at
+// https://gist.github.com/mathiasbynens/3b42c99a227521dabfe68d9e63f00f42.
+// Do not modify this file directly!
+
 const re = /\p{Emoji_Flag_Sequence}/u;
 
 assertTrue(re.test('\u{1F1E6}\u{1F1E8}'));

test/mjsunit/harmony/regexp-property-emoji-keycap-sequence-generated.js

-// Copyright 2018 the V8 project authors. All rights reserved.
+// Copyright 2019 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Flags: --harmony-regexp-sequence
 
+// These tests have been generated by the script at
+// https://gist.github.com/mathiasbynens/3b42c99a227521dabfe68d9e63f00f42.
+// Do not modify this file directly!
+
 const re = /\p{Emoji_Keycap_Sequence}/u;
 
 assertTrue(re.test('#\uFE0F\u20E3'));

test/mjsunit/harmony/regexp-property-emoji-modifier-sequence-generated.js

@@ -4,6 +4,9 @@
 
 // Flags: --harmony-regexp-sequence
 
+// TODO(mathias): Update these tests once a Unicode 12-friendly ICU
+// version rolls into V8.
+
 const re = /\p{Emoji_Modifier_Sequence}/u;
 
 assertTrue(re.test('\u261D\u{1F3FB}'));

test/mjsunit/harmony/regexp-property-emoji-tag-sequence-generated.js

-// Copyright 2018 the V8 project authors. All rights reserved.
+// Copyright 2019 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Flags: --harmony-regexp-sequence
 
+// These tests have been generated by the script at
+// https://gist.github.com/mathiasbynens/3b42c99a227521dabfe68d9e63f00f42.
+// Do not modify this file directly!
+
 const re = /\p{Emoji_Tag_Sequence}/u;
 
 assertTrue(re.test('\u{1F3F4}\u{E0067}\u{E0062}\u{E0065}\u{E006E}\u{E0067}\u{E007F}'));