Disallow cpp_locals and boolean binary operators (cython#6376)

It looks very difficult to handle correctly, so I'm not sure
it's worth the complication. A clean error message is better than
a compiler crash.

One part of cython#6370

Cython/Compiler/ExprNodes.py

@@ -14704,6 +14704,12 @@ def calculate_result_code(self):
     def generate_result_code(self, code):
         pass
 
+    def generate_bool_evaluation_code(self, *args, **kwds):
+        # This is enough of a corner-case that it probably isn't worth
+        # the corner-case of supporting it right now.
+        error(self.pos, "Using C++ classes in boolean binary operators with "
+                "the 'cpp_locals' directive is not currently supported.")
+
     def _make_move_result_rhs(self, result, optional=False):
         # this wouldn't normally get moved (because it isn't a temp), but force it to be because it
         # is a thin wrapper around a temp

tests/run/cpp_operators.pyx

@@ -1,5 +1,5 @@
 # mode: run
-# tag: cpp, werror
+# tag: cpp, werror, no-cpp-locals
 
 from __future__ import division