[clang] [llvm] [clangd] Add support for the c2000 architecture (PR #125663)

[James Nagurne via cfe-commits]

DragonDisciple wrote:

General comments:

- Please do not use tabs for spacing. This is what causes the unexpected whitespace gaps in the diff.
- There is a utility, clang-format-diff.py, which will assist in appeasing the code formatting check. However, I noticed running it myself that it changes some entire lists that should likely stay the way they are, so be careful!
  - My usual command line is something like: git diff -U0 --no-color --relative HEAD~1..HEAD | /path/to/clang-format-diff.py -p1 -i -binary /path/to/clang-format(.exe)
- Is there no desire to catch and support C2000 built-in functions? Those will show up in clangd as undefined symbols and will be errors in c99 or later, and in all C++ modes.
- Options
  - The options parser for clang and for the TI compilers are obviously very different. Some options interact with others for the purposes of ease-of-use and error checking, which is something that the clang options parser won't understand. I'll do my best to be diligent in case I have to point this out
  - There are many more options than the ones currently captured. Is it important we get as many as we can? Otherwise this will be a PR that is tailor-fit to a single use-case.

https://github.com/llvm/llvm-project/pull/125663