[DO NOT COMMIT][mlir] modernizer for ODS OpBuilder syntax

[ftynse]

Summary

This is a temporary tool to update the syntax of OpBuilder in ODS so that it
uses the dag-based version. It is based on a relatively simple parser and
formatter, which may require minor manual corrections.

Usage: mlir-tblgen-modernize filename.td

[ftynse]

Support more cases for $_builder and $_state