Remove obsolete, unused C++ test.

tests/compile/cpp_operators.pyx

-# tag: cpp
-# mode: compile
-
-cdef extern from "operators.h":
-    cdef cppclass Operators:
-        Operators(int)
-        Operators operator+(Operators)
-        Operators __add__(Operators, Operators)
-        Operators __sub__(Operators, Operators)
-        Operators __mul__(Operators, Operators)
-        Operators __div__(Operators, Operators)
-        bool __lt__(Operators, Operators)
-        bool __le__(Operators, Operators)
-        bool __eq__(Operators, Operators)
-        bool __ne__(Operators, Operators)
-        bool __gt__(Operators, Operators)
-        bool __ge__(Operators, Operators)
-        Operators __rshift__(Operators, int)
-        Operators __lshift__(Operators, int)
-        Operators __mod__(Operators, int)
-
-cdef int v = 10
-cdef Operators a
-cdef Operators b
-cdef Operators c
-
-c = a + b
-c = a - b
-c = a * b
-c = a / b
-c = a << 2
-c = a >> 1
-c = b % 2
-a < b
-a <= b
-a == b
-a != b
-a > b
-a >= b
-