improve perf of asString

[Uzlopak]

running only the first 4 benchmarks with maxSamples 100 (or else it takes gazillion years

before:

short string............................................. x 27,631,407 ops/sec ±0.44% (192 runs sampled)
short string with double quote........................... x 8,093,221 ops/sec ±0.59% (191 runs sampled)
long string without double quotes........................ x 26,659 ops/sec ±0.28% (193 runs sampled)
long string.............................................. x 11,697 ops/sec ±0.19% (192 runs sampled)

after:

short string............................................. x 43,111,798 ops/sec ±0.96% (187 runs sampled)
short string with double quote........................... x 13,393,581 ops/sec ±0.39% (191 runs sampled)
long string without double quotes........................ x 26,907 ops/sec ±0.20% (192 runs sampled)
long string.............................................. x 11,751 ops/sec ±0.23% (191 runs sampled)

Actually: Why 42?

Checklist

• run npm run test and npm run benchmark
• tests and/or benchmarks are included
• documentation is changed or added
• commit message and code follows the Developer's Certification of Origin
  and the Code of conduct

[mcollina]

lgtm

[mcollina]

Why 42?

It's a reference to Douglas Adams' “The Hitchhiker's Guide to the Galaxy,” because that number is the answer given by a supercomputer to “the Ultimate Question of Life, the Universe, and Everything.”