[clang-format] Support of TableGen value annotations. (#80299)

This implements the annotation of the values in TableGen.
The main changes are,

- parseTableGenValue(), the simplified parser method for the syntax of
values.
- modified consumeToken() to parseTableGenValue in 'if', 'assert' and
after '='.
- modified parseParens() to call parseTableGenValue inside.
- modified parseSquare() to to call parseTableGenValue inside, with
skipping separator tokens.
- modified parseAngle() to call parseTableGenValue inside, with skipping
separator tokens.