On 64-bit MSVC, pointers are 64 bit but `long` is only 32.
Thus, casting string to `unsigned long`, which is redundand on other
platforms, throws away important bits and when later cast to `intptr_t`
results in corrupt pointer.
This patch fixes test-parse-options by replacing harming cast with
correct one.
Signed-off-by: Marat Radchenko <marat@slonopotamus.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>