Codegen of vkjson

The vkjson_generate.py script generates vkjson files from data in
vkjson_constants.py. While ideally vk.xml would serve as the source (a
future improvement), deriving vkjson_constants.py from vk.xml is a
separate task. To maintain concise CLs, this derivation will be
addressed in a separate CL. Adding symbols (features, properties,
extensions, limits) to vkjson is now straightforward. Simply define
their dependencies within vkjson_constants.py, and the script will
automatically update vkjson.h, vkjson.cc, and vkjson_instance.cc
accordingly.

Test: adb shell cmd gpu vkjson
Flag: NONE infeasible
Bug: b/401180969

Change-Id: I3652e80c465145e86cc4c25f79523a6dc2111d18

Author: guptaniki5051

vulkan/scripts/code_generator.py

@@ -21,6 +21,7 @@
 import driver_generator
 import generator_common
 import null_generator
+import vkjson_generator
 
 if __name__ == '__main__':
   generator_common.parse_vulkan_registry()
@@ -30,3 +31,6 @@
   driver_generator.gen_cpp()
   null_generator.gen_h()
   null_generator.gen_cpp()
+  vkjson_generator.gen_h()
+  vkjson_generator.gen_cc()
+  vkjson_generator.gen_instance_cc()