This adds support for most of the remaining LLVM command line tools
using a generic, generated wrapper. The subcommand interface for these
is (much) less interesting than our other subcommands, but it gives us
a uniform and consistent layer.
Note that I structured these as nested sub-sub-commands below an `llvm`
subcommand because of an expectation that we will want to add more, and
ones that don't use this generic layer. Some concrete future work:
- Add the `opt` and `llc` tools as subcommands for easier debugging and
experimentation with LLVM IR output from Carbon's toolchain.
- Potentially sink `lld` below the `llvm` layer given that it has
significantly less user visibility than commands like `clang`.
Unfortunately, the current driver subcommand APIs make nested
subcommands awkward. I've added a somewhat rough hack here to let the
LLVM tools go in, but there are some TODOs that I want to address in
a follow-up that works to adjust the structure of this code to be more
conducive to nesting like this.
Depends on #5048 -- only the last commit should be reviewed here.
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Co-authored-by: Geoff Romer <gromer@google.com>
Thomas Köppe
Chandler CarruthandGeoff Romer