Integrate VAST driver properly (#553)

* index: Refactor vast codegen integration.

* index: Make codegen use vast visitor list.

* git: Bump VAST and use master branch.

* Bump vast.

* Delete most auto-generated files

* Re-generate auto-generated files.

* Re-generate Python bindings.

* Pass CXX flags to rocksdb build config (#551)

* API to list the declarations overlapping macro expansion (#552)

* Add API to list declarations containing in macro expansions

* Update to overlapping and covering implementation

* Abstract out the common code to utility function

* Update python bindings

* address review comments and add checks for macro token reader

* Move overlapping APIs to TokenRange and update python bindings

* index: Refactor vast codegen integration.

* index: Make codegen use vast visitor list.

* git: Bump VAST and use master branch.

* Bump vast.

* Delete most auto-generated files

* Re-generate auto-generated files.

* Re-generate Python bindings.

* Fix to use entity ids for names. Update code style to match most other code style in mx.

* Add aggregate type interface

* Bug fix.

* Bug fix

* Hopeful fix for misidentification of definitions.

* Make nested classes in template specializations into nested fragments so that they can be subject to replacement.

---------

Co-authored-by: Peter Goodman <[email protected]>
Co-authored-by: kumarak <[email protected]>

.gitmodules

@@ -51,7 +51,6 @@
 [submodule "vendor/vast/src"]
 	path = vendor/vast/src
 	url = https://github.com/trailofbits/vast.git
-	branch = mx_codegen
 [submodule "vendor/intervaltree/src"]
 	path = vendor/intervaltree/src
 	url = https://github.com/ekg/intervaltree.git