layers: Add VK_NV_clip_space_w_scaling

Added support for VK_NV_clip_space_w_scaling to the validation
layers.
diff --git a/layers/state_tracker.cpp b/layers/state_tracker.cpp
index 89cd771..377077d 100644
--- a/layers/state_tracker.cpp
+++ b/layers/state_tracker.cpp
@@ -2470,6 +2470,9 @@
                 case VK_DYNAMIC_STATE_LINE_STIPPLE_EXT:
                     flags &= ~CBSTATUS_LINE_STIPPLE_SET;
                     break;
+                case VK_DYNAMIC_STATE_VIEWPORT_W_SCALING_NV:
+                    flags &= ~CBSTATUS_VIEWPORT_W_SCALING_SET;
+                    break;
                 default:
                     break;
             }
@@ -2686,6 +2689,13 @@
     }
 }
 
+void ValidationStateTracker::PreCallRecordCmdSetViewportWScalingNV(VkCommandBuffer commandBuffer, uint32_t firstViewport,
+                                                                   uint32_t viewportCount,
+                                                                   const VkViewportWScalingNV *pViewportWScalings) {
+    CMD_BUFFER_STATE *cb_state = GetCBState(commandBuffer);
+    cb_state->status |= CBSTATUS_VIEWPORT_W_SCALING_SET;
+}
+
 void ValidationStateTracker::PreCallRecordCmdSetLineWidth(VkCommandBuffer commandBuffer, float lineWidth) {
     CMD_BUFFER_STATE *cb_state = GetCBState(commandBuffer);
     cb_state->status |= CBSTATUS_LINE_WIDTH_SET;