test: fix flaky test-fs-watch-encoding on OS X

[Trott]

Checklist

• make -j4 test (UNIX) or vcbuild test nosign (Windows) passes
• the commit message follows commit guidelines

Affected core subsystem(s)

test fs

Description of change

Depends on #7327. More info after that lands...

Copy of shell script used to stress test locally for the problem:

#!/bin/bash

BASE_PATH=./test/parallel
TEST=$1
COPIES=$2

for i in `seq 1 $COPIES`;
do
  cp $BASE_PATH/$TEST.js $BASE_PATH/$TEST-$i.js
done

runcount=1
while true; do
  echo "Run ${runcount}"
  /usr/bin/python tools/test.py --timeout=5 --mode=release parallel/${TEST}* -J
  if [ $? -ne 0 ]; then
    break
  fi
  ((runcount++))
done

Script (named stress.sh in the project root) instantiated with: bash stress.sh test-fs-watch-encoding 4

Without change in this PR, it fails after a handful of runs, usually less than 10 and never more than 100. With this change, it does not seem to fail at all.

[Trott]

R=@santigimeno

[Trott]

CI: https://ci.nodejs.org/job/node-test-pull-request/3047/

[bnoordhuis]

s/our/out/

[bnoordhuis]

LGTM with typo.

[santigimeno]

LGTM

[santigimeno]

You can remove this. The test now passes in FreeBSD because of the interval

[Trott]

Rebased, nits fixed, force pushed, new CI: https://ci.nodejs.org/job/node-test-pull-request/3051/

[Trott]

CI again: https://ci.nodejs.org/job/node-test-pull-request/3052/ Hooray, yellow, not red, I'll take it.

[Trott]

Landed in 5267f29

[MylesBorins]

@Trott lts?

[Trott]

@thealphanerd No.