benchmark: increase iteration counts for 4 cases
Increase the iteration counts to 10X to reflect real performance of perf hooks timing.
Refs: https://github.com/nodejs/node/issues/50571
Belowing are the improved ratio with 10X iteration:
performance-observer.js ./node/benchmark//perf_hooks/performance-observer.js n=1000000 perf_hooks/performance-observer.js pending=1 n=1000000 percent=111.33% perf_hooks/performance-observer.js pending=10 n=1000000 percent=127.58%
resourcetiming.js ./node/benchmark//perf_hooks/resourcetiming.js n=1000000 perf_hooks/resourcetiming.js observe="resource" n=1000000 percent=135.24%
timerfied.js ./node/benchmark//perf_hooks/timerfied.js n=1000000 perf_hooks/timerfied.js observe="function" n=1000000 percent=116.11%
usertiming.js ./node/benchmark//perf_hooks/usertiming.js n=1000000 perf_hooks/usertiming.js observe="all" n=1000000 percent=823.76% perf_hooks/usertiming.js observe="measure" n=1000000 percent=1039.62%