vulkan_entrypoints_gen: For Windows ARM64EC, prefix symbols with '#'

Acked-by: Jason Ekstrand <jason.ekstrand@collabora.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/17267>

src/vulkan/util/vk_entrypoints_gen.py

@@ -128,6 +128,9 @@ TEMPLATE_C = Template(COPYRIGHT + """
       % endfor
 #else
     #pragma comment(linker, "/alternatename:${p}_${e.name}=vk_entrypoint_stub")
+#if defined(_M_ARM64EC)
+    #pragma comment(linker, "/alternatename:#${p}_${e.name}=#vk_entrypoint_stub")
+#endif
 #endif
 #else
     VKAPI_ATTR ${e.return_type} VKAPI_CALL ${p}_${e.name}(${e.decl_params()}) __attribute__ ((weak));