fixes https://github.com/llvm/llvm-project/issues/146866
The CLI and `.arch_extension` use a different list of features, and some
features that the CLI supports cannot currently be toggled using
`.arch_extension`. This PR fixes that, adding support for
`.arch_extension` for the following features:
- `dit`
- `brbe`
- `bti`
- `fcma`
- `jscvt`
- `pauth`
- `ssve`
- `wfxt`
The issue discusses that it is unfortunate that command line flag
parsing and assembly parsing don't share the infrastructure for
recognizing features, which can lead to inconsistencies like here. I
don't really see how I can combine them though, so for now this change
will fix the immediate problem.
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Co-authored-by: David Spickett <david.spickett@linaro.org>
933960134b