Adjust CO_FUTURE_ flags to match Python 3.8 changes, and add some m…

…issing flags

Fixes #504

pyc_code.cpp

@@ -64,6 +64,13 @@ void PycCode::load(PycData* stream, PycModule* mod)
     else
         m_flags = 0;
 
+    if (mod->verCompare(3, 8) < 0) {
+        // Remap flags to new values introduced in 3.8
+        if (m_flags & 0xF0000000)
+            throw std::runtime_error("Cannot remap unexpected flags");
+        m_flags = (m_flags & 0xFFFF) | ((m_flags & 0xFFF0000) << 4);
+    }
+
     m_code = LoadObject(stream, mod).cast<PycString>();
     m_consts = LoadObject(stream, mod).cast<PycSequence>();
     m_names = LoadObject(stream, mod).cast<PycSequence>();

pyc_code.h

@@ -12,23 +12,29 @@ class PycCode : public PycObject {
 public:
     typedef std::vector<PycRef<PycString>> globals_t;
     enum CodeFlags {
-        CO_OPTIMIZED = 0x1,
-        CO_NEWLOCALS = 0x2,
-        CO_VARARGS = 0x4,
-        CO_VARKEYWORDS = 0x8,
-        CO_NESTED = 0x10,
-        CO_GENERATOR = 0x20,
-        CO_NOFREE = 0x40,
-        CO_COROUTINE = 0x80,
-        CO_ITERABLE_COROUTINE = 0x100,
-        CO_GENERATOR_ALLOWED = 0x1000,
-        CO_FUTURE_DIVISION = 0x2000,
-        CO_FUTURE_ABSOLUTE_IMPORT = 0x4000,
-        CO_FUTURE_WITH_STATEMENT = 0x8000,
-        CO_FUTURE_PRINT_FUNCTION = 0x10000,
-        CO_FUTURE_UNICODE_LITERALS = 0x20000,
-        CO_FUTURE_BARRY_AS_BDFL = 0x40000,
-        CO_FUTURE_GENERATOR_STOP = 0x80000,
+        CO_OPTIMIZED = 0x1,                                 // 1.3 ->
+        CO_NEWLOCALS = 0x2,                                 // 1.3 ->
+        CO_VARARGS = 0x4,                                   // 1.3 ->
+        CO_VARKEYWORDS = 0x8,                               // 1.3 ->
+        CO_NESTED = 0x10,                                   // 2.1 ->
+        CO_GENERATOR = 0x20,                                // 2.2 ->
+        CO_NOFREE = 0x40,                                   // 2.3 ->
+        CO_COROUTINE = 0x80,                                // 3.5 ->
+        CO_ITERABLE_COROUTINE = 0x100,                      // 3.5 ->
+        CO_ASYNC_GENERATOR = 0x200,                         // 3.6 ->
+        CO_GENERATOR_ALLOWED = 0x1000,                      // 2.3 only
+
+        // The FUTURE flags are shifted left 4 bits starting from Python 3.8
+        // Older versions are automatically mapped to the new values in load()
+        CO_FUTURE_DIVISION = 0x20000,                       // 2.3 - 2.7, 3.1 ->
+        CO_FUTURE_ABSOLUTE_IMPORT = 0x40000,                // 2.5 - 2.7, 3.1 ->
+        CO_FUTURE_WITH_STATEMENT = 0x80000,                 // 2.5 - 2.7, 3.1 ->
+        CO_FUTURE_PRINT_FUNCTION = 0x100000,                // 2.6 - 2.7, 3.1 ->
+        CO_FUTURE_UNICODE_LITERALS = 0x200000,              // 2.6 - 2.7, 3.1 ->
+        CO_FUTURE_BARRY_AS_BDFL = 0x400000,                 // 3.1 ->
+        CO_FUTURE_GENERATOR_STOP = 0x800000,                // 3.5 ->
+        CO_FUTURE_ANNOTATIONS = 0x1000000,                  // 3.7 ->
+        CO_NO_MONITORING_EVENTS = 0x2000000,                // 3.13 ->
     };
 
     PycCode(int type = TYPE_CODE)