The `import_array()` macro, that defined a C code block that included a
return, was not handled correctly. The fix here is to cdef a replacement
`import_array` function with a defined error return. The new function is
a slight variation of the corresponding function defined by Cython.

DOC: Wrong return type of np.random.choice and wrong variable name in parameter description.

It's funny because it's fine in EXAMPLE_DOCSTRING.rst.txt that uses the
same example.

in parameter description.

[ci skip]

Valgrind complains about memcpy with overlapping address in mtrand.c
It happens when i == j in this loop.

Closer inspection the i == j iteration is not needed (it is a swap).
So, skip it and avoid depending on undefined behavior of memcpy.

related read:

https://sourceware.org/bugzilla/show_bug.cgi?id=12518

After #8883 was merged it was noticed that the same problem was
occuring with calls to PyInt_AsLong. Namely that PyErr_Occoured
wasn't being checked if it returned -1 indicating an exception
could have been thrown.

This PR adds those checks as well as a regression test.

There was an error in np.random.uniform where if np.random.uniform
were called with a type that throwed exceptions when it was converted
to a float this exception wouldn't be raised.

This bug was due to an issue where PyFloat_AsDouble was called but
no check for PyErr_Occurred was performed after.

This PR fixes the issue by ensuring that Cython will always emit a
call to PyErr_Occurred if PyFloat_AsDouble returns -1.0

Fixes: #8865