[Bug 49542] New: vkGetInstanceProcAddr shouldn't return an address for missing functions

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=49542

Bug ID: 49542
           Summary: vkGetInstanceProcAddr shouldn't return an address for
                    missing functions
           Product: Wine
           Version: 5.12
          Hardware: x86-64
                OS: Mac OS X
            Status: NEW
          Severity: normal
          Priority: P2
         Component: winevulkan
          Assignee: [e-mail]
          Reporter: [e-mail]

Created attachment 67677
  --> https://bugs.winehq.org/attachment.cgi?id=67677
+vulkan log

This causes test_enumerate_physical_device2() in vulkan-1/tests/vulkan.c to
crash on macOS.

It tries to call vkGetPhysicalDeviceProperties2 which is missing from MoltenVK.
The test has a skip if it can't find vkGetPhysicalDeviceProperties2, but it
isn't triggered.

The problem I've "found" is that macdrv_vkGetInstanceProcAddr correctly returns
NULL for vkGetPhysicalDeviceProperties2, but in the test it uses
vkGetInstanceProcAddr. vkGetInstanceProcAddr goes to wine_vkGetInstanceProcAddr
and that uses wine_vk_get_instance_proc_addr. 
wine_vk_get_instance_proc_addr doesn't return NULL, because it just checks some
sort of table.

Attached is a +vulkan log.

I'm running macOS 10.14, wine compiled with mingw and the 10.13 SDK.