Modify diagnostics to track which preset schema version corresponds to
the introduction of each diagnostic. Modify how we parse presets to use
the set of diagnostics to generate bindings, and to store diagnostics as
maps rather than as fixed members. Enforce that only diagnostics known
to the specified preset version are present.
This is a first and necessary step toward moving CMake's internals over
to flexible categories rather than each category having its own bespoke
variables and member functions.
Note that the presets documentation currently contains some broken
links, as it is anticipating further documentation updates that will
happen in a future commit.
Run the `clang-format.bash` script to update all our C and C++ code to a
new style defined by `.clang-format`, now with "east const" enforcement.
Use `clang-format` version 18.
* If you reached this commit for a line in `git blame`, re-run the blame
operation starting at the parent of this commit to see older history
for the content.
* See the parent commit for instructions to rebase a change across this
style transition commit.
Issue: #26123
`include-what-you-use` diagnostics, in practice, are specific to
the environment's compiler and standard library. Update includes
to satisfy IWYU for our CI job under Debian 12.
