Utilities: Rename CppParserTest => cpp-parser

This is a utility program that runs the LibCpp parser on a program and
dumps out the AST.

Userland/Utilities/cpp-parser.cpp

@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2021, the SerenityOS developers.
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include "AK/Forward.h"
+#include "LibCpp/AST.h"
+#include <LibCore/ArgsParser.h>
+#include <LibCore/File.h>
+#include <LibCpp/Parser.h>
+
+int main(int argc, char** argv)
+{
+    Core::ArgsParser args_parser;
+    const char* path = nullptr;
+    bool tokens_mode = false;
+    args_parser.add_option(tokens_mode, "Print Tokens", "tokens", 'T');
+    args_parser.add_positional_argument(path, "Cpp File", "cpp-file", Core::ArgsParser::Required::No);
+    args_parser.parse(argc, argv);
+
+    if (!path)
+        path = "Source/little/main.cpp";
+    auto file = Core::File::construct(path);
+    if (!file->open(Core::OpenMode::ReadOnly)) {
+        perror("open");
+        exit(1);
+    }
+    auto content = file->read_all();
+    StringView content_view(content);
+    ::Cpp::Parser parser(content_view, path);
+    if (tokens_mode) {
+        parser.print_tokens();
+        return 0;
+    }
+    auto root = parser.parse();
+
+    dbgln("Parser errors:");
+    for (auto& error : parser.errors()) {
+        dbgln("{}", error);
+    }
+
+    root->dump(0);
+}