builtin: add libbacktrace as option for generating stack traces (#14277)

vlib/builtin/builtin_test.v

@@ -0,0 +1,14 @@
+fn test_g_main_argc() {
+	assert g_main_argc > 0
+}
+
+fn test_g_main_argv() {
+	assert g_main_argv != 0
+	mut first_arg := ''
+	$if windows {
+		first_arg = unsafe { string_from_wide(&&u16(g_main_argv)[0]) }
+	} $else {
+		first_arg = unsafe { cstring_to_vstring(&&char(g_main_argv)[0]) }
+	}
+	assert first_arg.contains('builtin_test')
+}