Let compiled binaries pass `--help` through to `IO.args`

[noah-emp]

Behavior

A Bend-compiled native binary treats --help as a runtime flag. Before main runs, the runtime prints its own usage (--threads, --gpu, --gpu-build, --help, --) and exits. The program never sees --help in IO.args().

The same reserved handling applies to --threads, --gpu, and --gpu-build. Words after -- are passed through unchanged, including --help.

Minimal example

# demo.bend
import Base

def main() -> IO(Unit):
  do IO<Unit>:
    +av : List<&1, String> <- IO.args()
    match av:
      case Con{h, _t}:
        IO.print(h)
      case Nil{}:
        IO.print("(none)")

Build and run:

bend demo.bend -o bin/demo
bin/demo --help          # runtime usage; process exits; demo does not run
bin/demo -- --help       # prints: --help
bin/demo hello           # prints: hello

Request

Prefer one of:

1. Pass --help through to IO.args() (move runtime help to something like --bend-help), or
2. Keep runtime --help only when the binary has no program arguments and/or when explicitly requested, and otherwise forward --help to the program.

Goal: a compiled CLI can implement its own --help the way users expect, without requiring help as a subcommand or -- --help.