[libfuzzer] moving icu fuzzers to //third_party/icu, additional fuzzers.

fuzzers/icu_unicode_string_codepage_create_fuzzer.cc

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <algorithm>
+#include <array>
+#include <vector>
+
+#include "third_party/icu/source/common/unicode/unistr.h"
+#include "third_party/icu/fuzzers/fuzzer_utils.h"
+
+// Taken from third_party/icu/source/data/mappings/convrtrs.txt file.
+static const std::array<const char*, 45> kConverters = {
+  {
+    "UTF-8",
+    "utf-16be",
+    "utf-16le",
+    "UTF-32",
+    "UTF-32BE",
+    "UTF-32LE",
+    "ibm866-html",
+    "iso-8859-2-html",
+    "iso-8859-3-html",
+    "iso-8859-4-html",
+    "iso-8859-5-html",
+    "iso-8859-6-html",
+    "iso-8859-7-html",
+    "iso-8859-8-html",
+    "ISO-8859-8-I",
+    "iso-8859-10-html",
+    "iso-8859-13-html",
+    "iso-8859-14-html",
+    "iso-8859-15-html",
+    "iso-8859-16-html",
+    "koi8-r-html",
+    "koi8-u-html",
+    "macintosh-html",
+    "windows-874-html",
+    "windows-1250-html",
+    "windows-1251-html",
+    "windows-1252-html",
+    "windows-1253-html",
+    "windows-1254-html",
+    "windows-1255-html",
+    "windows-1256-html",
+    "windows-1257-html",
+    "windows-1258-html",
+    "x-mac-cyrillic-html",
+    "windows-936-2000",
+    "gb18030",
+    "big5-html",
+    "euc-jp-html",
+    "ISO_2022,locale=ja,version=0",
+    "shift_jis-html",
+    "euc-kr-html",
+    "ISO-2022-KR",
+    "ISO-2022-CN",
+    "ISO-2022-CN-EXT",
+    "HZ-GB-2312"
+  }
+};
+
+// Entry point for LibFuzzer.
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  auto rng = CreateRng(data, size);
+  icu::UnicodeString str(reinterpret_cast<const char*>(data), size, 
+      kConverters[rng() % kConverters.size()]);
+  return 0;
+}