[icu] Support loading data file from default location

src/base/file-utils.cc

+// Copyright 2016 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.
+
+#include "src/base/file-utils.h"
+
+#include <string.h>
+
+#include "src/base/platform/platform.h"
+
+namespace v8 {
+namespace internal {
+
+char* RelativePath(char** buffer, const char* exec_path, const char* name) {
+  DCHECK(exec_path);
+  int path_separator = static_cast<int>(strlen(exec_path)) - 1;
+  while (path_separator >= 0 &&
+         !base::OS::isDirectorySeparator(exec_path[path_separator])) {
+    path_separator--;
+  }
+  if (path_separator >= 0) {
+    int name_length = static_cast<int>(strlen(name));
+    *buffer =
+        reinterpret_cast<char*>(calloc(path_separator + name_length + 2, 1));
+    *buffer[0] = '\0';
+    strncat(*buffer, exec_path, path_separator + 1);
+    strncat(*buffer, name, name_length);
+  } else {
+    *buffer = strdup(name);
+  }
+  return *buffer;
+}
+
+}  // namespace internal
+}  // namespace v8