As described in src/util/detect_os.h, the DETECT_OS macros are always
defined to a 0 or 1 value, and they should be used with #if rather
than #ifdef.
Commit 54b7227f15 accidentally disabled those extensions on all
platforms, so enable them again.
Fixes: 54b7227f15 ("egl/wgl: On win32, there is no support for EGL_EXT_device and EGL_EXT_platform_device")
Signed-off-by: Erico Nunes <nunes.erico@gmail.com>
Reviewed-by: Jesse Natalie <jenatali@microsoft.com>
Acked-by: Yonggang Luo <luoyonggang@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16751>