docs: kdoc: create a CMatch to match nested C blocks

docs: kdoc: create a CMatch to match nested C blocks

The NextMatch code is complex, and will become even more complex
if we add there support for arguments.

Now that we have a tokenizer, we can use a better solution,
easier to be understood.

Yet, to improve performance, it is better to make it use a
previously tokenized code, changing its ABI.

So, reimplement NextMatch using the CTokener class. Once it
is done, we can drop NestedMatch.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <fa818ea164216b17520b588e3f12b81499b76dd7.1773770483.git.mchehab+huawei@kernel.org>