[SV 54233] Preserve higher command_state values on also_make targets.

[SV 54233] Preserve higher command_state values on also_make targets.

If multiple pattern rules have the same pattern as also-make targets
and we attempt to run them at the same time, we might downgrade the
command state from 'running' to 'deps_running'; this will prevent
that also_make from being considered complete causing make to wait
forever for it to finish.

Ensure that set_command_state never downgrades the state of a target.

* src/file.c (set_command_state): Don't downgrade command_state.
* src/filedef.h (struct file): Document the order prerequisite.
* test/scripts/features/patternrules: Test the behavior.