add two new sys.flags which are set by CPython impl specific commandline flags

Author: timfel

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/SysModuleBuiltins.java

@@ -192,6 +192,8 @@ public void postInitialize(PythonCore core) {
                         PythonOptions.getFlag(context, PythonOptions.PythonOptimizeFlag), // optimize
                         PythonOptions.getFlag(context, PythonOptions.QuietFlag), // quiet
                         PythonOptions.getFlag(context, PythonOptions.VerboseFlag), // verbose
+                        false, // dev_mode
+                        0, // utf8_mode
         }));
 
         Env env = context.getEnv();

graalpython/lib-graalpython/sys.py

@@ -61,7 +61,7 @@ def make_flags_class():
     names = ["bytes_warning", "debug", "dont_write_bytecode",
              "hash_randomization", "ignore_environment", "inspect",
              "interactive", "isolated", "no_site", "no_user_site", "optimize",
-             "quiet", "verbose"]
+             "quiet", "verbose", "dev_mode", "utf8_mode"]
 
     flags_class = make_named_tuple_class("sys.flags", names)