Summary:
This is the first step (step 1 below) in a series of refactoring steps that will replace minibmg nodes with a distinct node type for each operations and a visitor mechanism.
Introduce Node2 and Node2Visitor (without tests yet)
Introduce Graph2 using Node2 with json I/O (ditto)
Introduce Tracing2 using Node2 (ditto)
Introduce Eval2 (ditto)
Migrate tests to Node2.
Migrate any remaining pieces to Node2.
Delete Node.h and Node.cpp
Rename Node2 to Node and similarly for other types and files.
Summary: This is the first step (step 1 below) in a series of refactoring steps that will replace minibmg nodes with a distinct node type for each operations and a visitor mechanism.
Differential Revision: D40390955