[llvm-strings] Switch command line parsing from llvm::cl to OptTable
Some behavior changes:
- -t=d is removed. Use -t d instead.
- one-dash long options like -all are supported. Use --all instead.
- --all=0 or --all=false cannot be used. (Note: --all is silently ignored anyway)
- --help-list is removed. This is a cl:: specific option.
Nobody is likely leveraging any of the above.
- -t diagnostic gets improved.
- in the absence of HideUnrelatedOptions, --help will not list unrelated options if linking against libLLVM-13git.so or linker GC is not used.
- Decrease the probability of cl::opt collision if we do decide to support multiplexing
Note: because the tool is so simple, used more for forensics instead of a building
tool, and its long options are unlikely used in one-dash form, I just drop the
one-dash form in this patch.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D104889