[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.

tests/scripts/features/patternrules

@@ -220,6 +220,22 @@ all: foo.x foo-mt.x
 
 1;
 
+# Test pattern rules building the same targets
+# See SV 54233.  Rely on our standard test timeout to break the loop
+
+touch('a.c');
+
+run_make_test(q!
+all: a.elf a.dbg
+
+%.elf %.lnk: %.c ; : $*.elf $*.lnk
+
+%.elf %.dbg: %.lnk ; : $*.elf $*.dbg
+!,
+    '-j2', ": a.elf a.lnk\n: a.elf a.dbg\n");
+
+unlink('a.c');
+
 # This tells the test driver that the perl test script executed properly.
 1;