util: improve textencoder encodeInto performance

[anonrig]

Port of cloudflare/workerd#5448

Co-authored-by: Erik Corry (@erikcorry)
Co-authored-by: Daniel Lemire (@lemire)

This path can be optimized even more when Chromium PR (for updating simdutf https://chromium-review.googlesource.com/c/chromium/src/+/7199521) lands and v8 updates and includes it in a new release, and node.js updates v8 version...

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Benchmark CI: https://ci.nodejs.org/view/Node.js%20benchmark/job/benchmark-node-micro-benchmarks/1767/

confidence improvement accuracy (*)     (**)    (***)
15:32:37  util/text-encoder.js op='encode' type='ascii' n=1000000 len=1024                              -0.31 %       ±1.32%   ±1.75%   ±2.28%
15:32:37  util/text-encoder.js op='encode' type='ascii' n=1000000 len=256                                0.22 %       ±0.71%   ±0.94%   ±1.23%
15:32:37  util/text-encoder.js op='encode' type='ascii' n=1000000 len=32                         **     -1.24 %       ±0.84%   ±1.12%   ±1.46%
15:32:37  util/text-encoder.js op='encode' type='ascii' n=1000000 len=8192                      ***     -0.50 %       ±0.09%   ±0.12%   ±0.15%
15:32:37  util/text-encoder.js op='encode' type='one-byte-string' n=1000000 len=1024            ***      1.18 %       ±0.62%   ±0.82%   ±1.07%
15:32:37  util/text-encoder.js op='encode' type='one-byte-string' n=1000000 len=256                     -0.10 %       ±0.74%   ±0.98%   ±1.28%
15:32:37  util/text-encoder.js op='encode' type='one-byte-string' n=1000000 len=32               **     -1.24 %       ±0.91%   ±1.21%   ±1.57%
15:32:37  util/text-encoder.js op='encode' type='one-byte-string' n=1000000 len=8192                     0.01 %       ±0.06%   ±0.08%   ±0.11%
15:32:37  util/text-encoder.js op='encode' type='two-byte-string' n=1000000 len=1024            ***     -0.85 %       ±0.21%   ±0.29%   ±0.37%
15:32:37  util/text-encoder.js op='encode' type='two-byte-string' n=1000000 len=256             ***     -1.18 %       ±0.66%   ±0.87%   ±1.14%
15:32:37  util/text-encoder.js op='encode' type='two-byte-string' n=1000000 len=32                       0.43 %       ±1.01%   ±1.35%   ±1.76%
15:32:37  util/text-encoder.js op='encode' type='two-byte-string' n=1000000 len=8192            ***     -0.25 %       ±0.04%   ±0.05%   ±0.07%
15:32:37  util/text-encoder.js op='encodeInto' type='ascii' n=1000000 len=1024                  ***    654.06 %      ±14.64%  ±19.73%  ±26.20%
15:32:37  util/text-encoder.js op='encodeInto' type='ascii' n=1000000 len=256                   ***    197.67 %       ±7.34%   ±9.89%  ±13.13%
15:32:37  util/text-encoder.js op='encodeInto' type='ascii' n=1000000 len=32                    ***    -22.79 %       ±2.61%   ±3.48%   ±4.56%
15:32:37  util/text-encoder.js op='encodeInto' type='ascii' n=1000000 len=8192                  ***   1829.66 %      ±78.90% ±106.33% ±141.17%
15:32:37  util/text-encoder.js op='encodeInto' type='one-byte-string' n=1000000 len=1024        ***    163.76 %      ±11.41%  ±15.38%  ±20.42%
15:32:37  util/text-encoder.js op='encodeInto' type='one-byte-string' n=1000000 len=256         ***     32.93 %       ±1.07%   ±1.44%   ±1.89%
15:32:37  util/text-encoder.js op='encodeInto' type='one-byte-string' n=1000000 len=32           **     -4.92 %       ±3.31%   ±4.41%   ±5.75%
15:32:37  util/text-encoder.js op='encodeInto' type='one-byte-string' n=1000000 len=8192        ***    303.17 %       ±0.97%   ±1.30%   ±1.73%
15:32:37  util/text-encoder.js op='encodeInto' type='two-byte-string' n=1000000 len=1024        ***    108.52 %       ±3.18%   ±4.28%   ±5.69%
15:32:37  util/text-encoder.js op='encodeInto' type='two-byte-string' n=1000000 len=256         ***     13.48 %       ±0.82%   ±1.09%   ±1.43%
15:32:37  util/text-encoder.js op='encodeInto' type='two-byte-string' n=1000000 len=32            *     -2.42 %       ±2.22%   ±2.95%   ±3.84%
15:32:37  util/text-encoder.js op='encodeInto' type='two-byte-string' n=1000000 len=8192        ***    180.96 %       ±0.20%   ±0.27%   ±0.36%

[anonrig]

@RafaelGSS please take a look

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/70326/

[jasnell]

Suggested change

	v8::String::ValueView view(isolate, source);
	// Note: Take care not to perform any action in v8 that would
	// trigger GC as it could cause the view to become invalid.
	v8::String::ValueView view(isolate, source);

[jasnell]

A DCHECK for bounds checking would be nice here.

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/70345/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/70349/

[nodejs-github-bot]

Landed in b1e941e