[Phi] adding basic host emulation for development without access to a

Xeon Phi

src/phi/PhiInstance.zig

@@ -61,7 +61,8 @@ fn destroy(interface: *Interface, allocator: std.mem.Allocator) VkError!void {
     self.threaded.deinit();
     allocator.destroy(self);
 
-    mic.unload();
+    if (comptime !lib.config.phi_host_emulation)
+        mic.unload();
 }
 
 fn requestPhysicalDevices(interface: *Interface, allocator: std.mem.Allocator, _: []base.drm.Card) VkError!void {
@@ -69,6 +70,17 @@ fn requestPhysicalDevices(interface: *Interface, allocator: std.mem.Allocator, _
         return;
     }
 
+    if (comptime lib.config.phi_host_emulation) {
+        const physical_device = try PhiPhysicalDevice.createEmulated(allocator, interface);
+        errdefer physical_device.interface.release(allocator) catch @panic("Caught an error while handling an error");
+
+        const dispatchable = try Dispatchable(base.PhysicalDevice).wrap(allocator, &physical_device.interface);
+        errdefer dispatchable.destroy(allocator);
+
+        interface.physical_devices.append(allocator, dispatchable) catch return VkError.OutOfHostMemory;
+        return;
+    }
+
     mic.load() catch |err| {
         std.log.scoped(.MIC).err("Failed to load libmicmgmt: {s}", .{@errorName(err)});
         return VkError.InitializationFailed;