LLVM TblGen syntax hightlighter

Hi all,

  LLVM now is using Sphinx to generate it's documentation. For syntax
hightlighting, Sphinx uses Pygments [2]. Pygments already support LLVM
IR syntax, however it doesn't support LLVM tblgen. I wrote up a Pygments
extension that can be incorpreated in Sphinx [3]. After installing the
extension, you can write the code below and get hightlight tblgen
syntax.

.. code-block:: tblgen

  def FeatureFPU : SubtargetFeature<"fpu", "fpu", "true",
                                    "Enable FPU">;

  Any feedback is welcomed. If possible, I would like to make this
extension upstream to Pygments. :slight_smile:

Regards,
chenwj

[1] http://sphinx-doc.org/
[2] http://pygments.org/
[3] https://github.com/azru0512/tblgenlexer