lib,test,benchmark: simplify code with String.prototype.repeat()

[JacksonTian]

use String.prototype.repeat() to simplify code, less code, more
semantically.

[JacksonTian]

like #5311 .

[mscdex]

CI: https://ci.nodejs.org/job/node-test-pull-request/1715/

[mscdex]

Linter failed:

/usr/home/iojs/build/workspace/node-test-linter/test/parallel/test-buffer.js
684:7 error 's' is never modified, use 'const' instead prefer-const

[mscdex]

Also this test is failing on all platforms:

not ok 170 test-debugger-util-regression.js
# # assert.js:89
# throw new assert.AssertionError({
# ^
# AssertionError: the program should not hang
# at Object.exports.fail (/home/iojs/build/workspace/node-test-commit-linux/nodes/centos5-32/test/common.js:453:10)
# at fail [as _onTimeout] (/home/iojs/build/workspace/node-test-commit-linux/nodes/centos5-32/test/parallel/test-debugger-util-regression.js:23:10)
# at Timer.listOnTimeout (timers.js:92:15)

[JacksonTian]

Hi @mscdex , I updated the PR.

[mscdex]

CI again: https://ci.nodejs.org/job/node-test-pull-request/1717/

[mscdex]

CI is all green

[targos]

LGTM

[JacksonTian]

Rebased with master.

[jasnell]

LGTM

[jasnell]

Landed in 4d78121

[Trott]

@jasnell Landing this has broken make test because the linter is failing. CI was last run on this more than 4 weeks ago and some rules have been tightened since then. :-(

[Trott]

I'll put together a fix unless someone beats me to it.

[JacksonTian]

I am sorry, Let me fix it. @Trott .

[Trott]

I already opened #5840, but thanks!

[Trott]

(And no worries, this isn't the first time this sort of thing has happened, the problem is our process not anything you did wrong.)

[jasnell]

Yep, not your fault at all @JacksonTian ... I'm the one who missed the step. I saw the green CI without checking the date and forgot to run make lint locally before I pushed. It happens, unfortunately.

[Trott]

Yeah, we've got a lot of opportunities for automation, for sure.

[MylesBorins]

I've manually added the linting changes while backporting. @Trott I've marked your linting PR as don't land on v4