perf(lexer): use portable-SIMD to speed up multiline comment scanning

[Boshen]

No description provided.

[github-actions]

Parser Benchmark Results

group                    main                                   pr
-----                    ----                                   --
parser/babylon.max.js    1.06    150.8±2.27ms    68.5 MB/sec    1.00    142.4±2.67ms    72.5 MB/sec
parser/d3.js             1.00     18.1±0.36ms    30.2 MB/sec    1.01     18.3±0.32ms    29.8 MB/sec
parser/lodash.js         1.24      6.4±0.13ms    80.5 MB/sec    1.00      5.1±0.12ms   100.2 MB/sec
parser/pdf.js            1.00     10.3±0.17ms    39.1 MB/sec    1.01     10.4±0.20ms    38.7 MB/sec
parser/typescript.js     1.00    143.9±2.59ms    66.9 MB/sec    1.00    143.8±2.32ms    66.9 MB/sec

[strager]

I have found that to_bitmask on ARM NEON can be cause parsing to be slower compared to a scalar version. My block comment parser only uses SIMD on x86, not ARM. Do you run your benchmarks on ARM NEON or just Intel SSE?

On x86_64, to_bitmask is one instruction. On AArch64, there is no instruction and to_bitmask needs to be emulated. See: https://godbolt.org/z/531oEo5d1 It looks like the Rust compiler currently does a terrible job on AArch64. You can definitely do better by hand, but it still might not be faster than the scalar version.