Userland+AK: Stop using getopt() for ArgsParser

This commit moves the implementation of getopt into AK, and converts its
API to understand and use StringView instead of char*.
Everything else is caught in the crossfire of making
Option::accept_value() take a StringView instead of a char const*.

With this, we must now pass a Span<StringView> to ArgsParser::parse(),
applications using LibMain are unaffected, but anything not using that
or taking its own argc/argv has to construct a Vector<StringView> for
this method.

Userland/Libraries/LibTest/JavaScriptTestRunnerMain.cpp

@@ -56,6 +56,11 @@ static void handle_sigabrt(int)
 
 int main(int argc, char** argv)
 {
+    Vector<StringView> arguments;
+    arguments.ensure_capacity(argc);
+    for (auto i = 0; i < argc; ++i)
+        arguments.append({ argv[i], strlen(argv[i]) });
+
     g_test_argc = argc;
     g_test_argv = argv;
     auto program_name = LexicalPath::basename(argv[0]);
@@ -100,7 +105,7 @@ int main(int argc, char** argv)
         .help_string = "Show progress with OSC 9 (true, false)",
         .long_name = "show-progress",
         .short_name = 'p',
-        .accept_value = [&](auto* str) {
+        .accept_value = [&](StringView str) {
             if ("true"sv == str)
                 print_progress = true;
             else if ("false"sv == str)
@@ -120,7 +125,7 @@ int main(int argc, char** argv)
         args_parser.add_option(*entry.key, entry.value.get<0>().characters(), entry.value.get<1>().characters(), entry.value.get<2>());
     args_parser.add_positional_argument(specified_test_root, "Tests root directory", "path", Core::ArgsParser::Required::No);
     args_parser.add_positional_argument(common_path, "Path to tests-common.js", "common-path", Core::ArgsParser::Required::No);
-    args_parser.parse(argc, argv);
+    args_parser.parse(arguments);
 
     if (per_file)
         print_json = true;

Userland/Libraries/LibTest/TestMain.cpp

@@ -22,7 +22,13 @@ int TEST_MAIN(int argc, char** argv)
         warnln("Test main does not have a valid test name!");
         return 1;
     }
-    int ret = ::Test::TestSuite::the().main(argv[0], argc, argv);
+
+    Vector<StringView> arguments;
+    arguments.ensure_capacity(argc);
+    for (auto i = 0; i < argc; ++i)
+        arguments.append({ argv[i], strlen(argv[i]) });
+
+    int ret = ::Test::TestSuite::the().main(argv[0], arguments);
     ::Test::TestSuite::release();
     return ret;
 }

Userland/Libraries/LibTest/TestSuite.cpp

@@ -56,7 +56,7 @@ void set_suite_setup_function(Function<void()> setup)
     TestSuite::the().set_suite_setup(move(setup));
 }
 
-int TestSuite::main(DeprecatedString const& suite_name, int argc, char** argv)
+int TestSuite::main(DeprecatedString const& suite_name, Span<StringView> arguments)
 {
     m_suite_name = suite_name;
 
@@ -71,7 +71,7 @@ int TestSuite::main(DeprecatedString const& suite_name, int argc, char** argv)
     args_parser.add_option(do_benchmarks_only, "Only run benchmarks.", "bench", 0);
     args_parser.add_option(do_list_cases, "List available test cases.", "list", 0);
     args_parser.add_positional_argument(search_string, "Only run matching cases.", "pattern", Core::ArgsParser::Required::No);
-    args_parser.parse(argc, argv);
+    args_parser.parse(arguments);
 
     if (m_setup)
         m_setup();

Userland/Libraries/LibTest/TestSuite.h

@@ -33,7 +33,7 @@ public:
     }
 
     int run(NonnullRefPtrVector<TestCase> const&);
-    int main(DeprecatedString const& suite_name, int argc, char** argv);
+    int main(DeprecatedString const& suite_name, Span<StringView> arguments);
     NonnullRefPtrVector<TestCase> find_cases(DeprecatedString const& search, bool find_tests, bool find_benchmarks);
     void add_case(NonnullRefPtr<TestCase> const& test_case)
     {