zink: add more c++ guards to headers

Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18135>

src/gallium/drivers/zink/zink_kopper.h

@@ -30,6 +30,10 @@
 #include "kopper_interface.h"
 #include "u_queue.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 struct kopper_swapchain_image {
    bool init;
    bool acquired;
@@ -141,4 +145,9 @@ void
 zink_kopper_set_swap_interval(struct pipe_screen *pscreen, struct pipe_resource *pres, int interval);
 int
 zink_kopper_query_buffer_age(struct pipe_context *pctx, struct pipe_resource *pres);
+
+#ifdef __cplusplus
+}
+#endif
+
 #endif

src/gallium/drivers/zink/zink_resource.h

@@ -31,6 +31,9 @@
 #define ZINK_BIND_TRANSIENT (1 << 30) //transient fb attachment
 #define ZINK_BIND_VIDEO (1 << 31)
 
+#ifdef __cplusplus
+extern "C" {
+#endif
 
 bool
 zink_screen_resource_init(struct pipe_screen *pscreen);
@@ -81,7 +84,9 @@ zink_is_swapchain(const struct zink_resource *res)
    return res->swapchain;
 }
 
-#ifndef __cplusplus
+#ifdef __cplusplus
+}
+#else
 #include "zink_batch.h"
 #include "zink_bo.h"
 
@@ -141,4 +146,5 @@ zink_resource_object_usage_unset(struct zink_resource_object *obj, struct zink_b
 }
 
 #endif
+
 #endif