The rust compiler or linker (I'm not sure which) emits .debug_pubnames
and .debug_pubtypes sections in the binaries. They are supposed to speed
up launching a debugger, but they're obsolete. They've been superseded
by .debug_names section in more recent DWARF spec and debuggers, and
gdb and lldb just ignores them.
I could not find any way to prevent rustc / ldb / mold from emitting
these sections in the first place. So this commit adds a hack to strip
them off afterwards. This makes the binaries about 30% smaller, with
the downside of adding about 30 s to the build time in CI. That seems
like a good tradeoff, as smaller binaries can speed up other steps.
