Adding cython v0.20.2 in third-party.

third_party/cython/src/Cython/Includes/cpython/complex.pxd

Index: third_party/cython/src/Cython/Includes/cpython/complex.pxd
diff --git a/third_party/cython/src/Cython/Includes/cpython/complex.pxd b/third_party/cython/src/Cython/Includes/cpython/complex.pxd
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index 0000000000000000000000000000000000000000..f5ba339575a25d01035bc78c556f0eb8f75e7988
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+++ b/third_party/cython/src/Cython/Includes/cpython/complex.pxd
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+
+cdef extern from "Python.h":
+
+    ctypedef struct Py_complex:
+        double imag
+        double real
+
+    ############################################################################
+    # 7.2.5.2 Complex Numbers as Python Objects
+    ############################################################################
+
+    # PyComplexObject
+    # This subtype of PyObject represents a Python complex number object.
+
+    ctypedef class __builtin__.complex [object PyComplexObject]:
+        cdef Py_complex cval
+        # not making these available to keep them read-only:
+        #cdef double imag "cval.imag"
+        #cdef double real "cval.real"
+
+    # PyTypeObject PyComplex_Type
+    # This instance of PyTypeObject represents the Python complex
+    # number type. It is the same object as complex and
+    # types.ComplexType.
+
+    bint PyComplex_Check(object p)
+    # Return true if its argument is a PyComplexObject or a subtype of
+    # PyComplexObject.
+
+    bint PyComplex_CheckExact(object p)
+    # Return true if its argument is a PyComplexObject, but not a subtype of PyComplexObject.
+
+    object PyComplex_FromCComplex(Py_complex v)
+    # Return value: New reference.
+    # Create a new Python complex number object from a C Py_complex value.
+
+    object PyComplex_FromDoubles(double real, double imag)
+    # Return value: New reference.
+    # Return a new PyComplexObject object from real and imag.
+
+    double PyComplex_RealAsDouble(object op) except? -1
+    # Return the real part of op as a C double.
+
+    double PyComplex_ImagAsDouble(object op) except? -1
+    # Return the imaginary part of op as a C double.
+
+    Py_complex PyComplex_AsCComplex(object op)
+    # Return the Py_complex value of the complex number op.
+    #
+    # Returns (-1+0i) in case of an error