[MLIR][Pygments] Refine the pygments MLIR lexer (#166406)
Recently, the MLIR website added API documentation for the Python
bindings generated via Sphinx
([https://mlir.llvm.org/python-bindings/](https://mlir.llvm.org/python-bindings/)).
In
[https://github.com/llvm/mlir-www/pull/245](https://github.com/llvm/mlir-www/pull/245),
I introduced the Pygments lexer from the MLIR repository to enable
syntax highlighting for MLIR code blocks in these API docs.
However, since the existing Pygments lexer was fairly minimal, it didn’t
fully handle all aspects of the MLIR syntax, leading to imperfect
highlighting in some cases. In this PR, I used ChatGPT to rewrite the
lexer by combining it with the TextMate grammar for MLIR
([https://github.com/llvm/llvm-project/blob/main/mlir/utils/textmate/mlir.json](https://github.com/llvm/llvm-project/blob/main/mlir/utils/textmate/mlir.json)).
After some manual adjustments, the results look good—so I’m submitting
this to improve the syntax highlighting experience in the Python
bindings API documentation.
