Fix XFailed test x86stdcall

There was a syntax error because the `extern "stdcall"` was outside the module instead of inside it.

* moved `extern` inside module
* updated copyright dates
Updated PR to fix for feedback - only run on win32 (not win64) and use extern "system"

* change `cfg(target_os="win32")` to `cfg(windows)`
* change `extern "stdcall"` to `extern "system"`
* only run on Windows && x86, (not x86_64)