layers: Kill false thread errors re: command pool

Change the transitivity of usage counters such that only externally
synchronized command buffers mark their command pool as being an active
writer.

Added additional tracking for non-externally sync'd command buffers
s.t. command pool reset and destroy operations detect usage races.

Change-Id: I839ac8a5902a42ea1a1ba72db37cda2466516d11
diff --git a/scripts/threading_generator.py b/scripts/threading_generator.py
index 5cfb4d7..74d4b8c 100644
--- a/scripts/threading_generator.py
+++ b/scripts/threading_generator.py
@@ -376,6 +376,8 @@
             'vkDestroyInstance',
             'vkAllocateCommandBuffers',
             'vkFreeCommandBuffers',
+            'vkResetCommandPool',
+            'vkDestroyCommandPool',
             'vkCreateDebugReportCallbackEXT',
             'vkDestroyDebugReportCallbackEXT',
             'vkAllocateDescriptorSets',