These test fails with C++ on Cygwin due to lack of long double functions. This...

These test fails with C++ on Cygwin due to lack of long double functions. This was not a problem in plain C, but the C++ compiler is stricter about undeclared functions.  Better to skip them anyways.

tests/cygwin_bugs.txt

+complex_numbers_c89_T398_long_double
+complex_numbers_T305_long_double
 int_float_builtins_as_casts_T400_long_double

tests/run/complex_numbers_T305.pyx

@@ -5,14 +5,13 @@ cimport cython
 def test_object_conversion(o):
     """
     >>> test_object_conversion(2)
-    ((2+0j), (2+0j), (2+0j))
+    ((2+0j), (2+0j))
     >>> test_object_conversion(2j - 0.5)
-    ((-0.5+2j), (-0.5+2j), (-0.5+2j))
+    ((-0.5+2j), (-0.5+2j))
     """
     cdef float complex a = o
     cdef double complex b = o
-    cdef long double complex c = o
-    return (a, b, c)
+    return (a, b)
 
 def test_arithmetic(double complex z, double complex w):
     """

tests/run/complex_numbers_T305_long_double.pyx

+# ticket: 305
+
+cimport cython
+
+def test_object_conversion(o):
+    """
+    >>> test_object_conversion(2)
+    (2+0j)
+    >>> test_object_conversion(2j - 0.5)
+    (-0.5+2j)
+    """
+    cdef long double complex a = o
+    return a

tests/run/complex_numbers_c89_T398_long_double.pyx

+# ticket: 398
+
+cdef extern from "complex_numbers_c89_T398.h": pass
+include "complex_numbers_T305_long_double.pyx"