https://github.com/KhronosGroup/Vulkan-ValidationLayers/issues
Fix static_assert(sizeof(Slot) == 32) on 32-bit platforms. On 32-bit x86,
uint64_t has 4-byte alignment, so the Data union inside Entry lands at
offset 12 instead of 16 and Slot ends up 28 bytes, breaking both the
static_assert and the CPU->GPU layout the descriptor_heap shader expects
(key@0, types@8, data@16). Force 8-byte alignment on the Data member so
Entry (and thus Slot) matches the 64-bit layout on all platforms.

--- a/layers/state_tracker/descriptor_hashing.h
+++ b/layers/state_tracker/descriptor_hashing.h
@@ -57,7 +57,7 @@ struct DescriptorHashTable {
         bool HasType(VkDescriptorType vk_type) const;
         bool IsNullDescriptor() const;
 
-        union Data {
+        alignas(8) union Data {
             EntryBuffer buffer;
             EntryImage image;
             EntrySampler sampler;