runners: bench: Added BENCH_SIMTIME/SIMRESET/PAUSE/RESUME/etc

- BENCH_SIMTIME()   => lfs3_kiwibd_simtime()
- BENCH_SIMRESET()  => lfs3_kiwibd_simreset()
- BENCH_SIMPAUSE()  => lfs3_kiwibd_simpause()
- BENCH_SIMRESUME() => lfs3_kiwibd_simresume()
- BENCH_RESET()     => lfs3_kiwibd_simreset() + BENCH_STACK/HEAP_RESET()
- BENCH_PAUSE()     => lfs3_kiwibd_simpause() + BENCH_STACK/HEAP_PAUSE()
- BENCH_RESUME()    => lfs3_kiwibd_simresume() + BENCH_STACK/HEAP_RESUME()

This does two things:

1. Adds pause/resume counters to bd counters to make it easier to
   exclude operations from the current bench (potentially useful for
   seq+disk usage).

2. Exposes bd simtime operations as BENCH_* macros, to make it a bit
   easier to interact with simtime without tying all the benches to
   kiwibd. (Not that we'll ever probably not use kiwibd, but still).

Also adopted 32-bit counters for stack/heap pause state instead of a
32-bit stack. Not that either are at a risk of overflowing, but better
safe than sorry.

Makefile

@@ -701,9 +701,9 @@ bench-widths: $(BENCH_CSV)
 		$(SUMMARYFLAGS))
 
 ## Show heap/stack/disk usage
-.PHONY: bench-usage
-bench-usage: SUMMARYFLAGS+=-Si
-bench-usage: $(BENCH_CSV)
+.PHONY: bench-ram bench-usage
+bench-ram bench-usage: SUMMARYFLAGS+=-Si
+bench-ram bench-usage: $(BENCH_CSV)
 	$(strip ./scripts/csv.py \
 		<(./scripts/csv.py $^ \
 			-Dprobe=stack \