use /usr/bin/time to collect runtime and memory

perf

@@ -3,6 +3,6 @@ set -e
 # Wrapper script to use perf as TIMECMD for the build.
 
 VFILE="${!#}"
-perf stat -o "$VFILE.perf.tmp" -x ';' -e instructions,cycles -- "$@"
-(echo "## $VFILE" && (cat "$VFILE.perf.tmp" | egrep -v '^(# .*)?$') && echo) > "$VFILE.perf"
-rm "$VFILE.perf.tmp"
+LC_ALL=C /usr/bin/time -o "$VFILE.time" -f "real: %e, user: %U, sys: %S, mem: %M kB" -- perf stat -o "$VFILE.counters" -x ';' -e instructions,cycles -- "$@"
+(echo "## $VFILE" && (cat "$VFILE.counters" | egrep -v '^(# .*)?$') && cat "$VFILE.time" && echo) > "$VFILE.perf"
+rm "$VFILE.counters" "$VFILE.time"