Improve Text.check performance

[naitoh]

The doctype parameter of Text.check is not being used.
Changing the doctype parameter to an optional parameter improves the parsing speed of the DOM.

Benchmark

 before after before(YJIT) after(YJIT) dom 19.854 23.805 33.969 37.712 i/s - 100.000 times in 5.036779s 4.200839s 2.943877s 2.651709s sax 29.436 30.494 54.070 55.089 i/s - 100.000 times in 3.397155s 3.279348s 1.849463s 1.815255s pull 34.908 34.857 62.969 64.895 i/s - 100.000 times in 2.864651s 2.868842s 1.588082s 1.540939s stream 34.570 34.281 60.616 60.355 i/s - 100.000 times in 2.892656s 2.917080s 1.649737s 1.656866s Comparison: dom after(YJIT): 37.7 i/s before(YJIT): 34.0 i/s - 1.11x slower after: 23.8 i/s - 1.58x slower before: 19.9 i/s - 1.90x slower sax after(YJIT): 55.1 i/s before(YJIT): 54.1 i/s - 1.02x slower after: 30.5 i/s - 1.81x slower before: 29.4 i/s - 1.87x slower pull after(YJIT): 64.9 i/s before(YJIT): 63.0 i/s - 1.03x slower before: 34.9 i/s - 1.86x slower after: 34.9 i/s - 1.86x slower stream before(YJIT): 60.6 i/s after(YJIT): 60.4 i/s - 1.00x slower before: 34.6 i/s - 1.75x slower after: 34.3 i/s - 1.77x slower 

• YJIT=ON : 1.00x - 1.11x faster (dom: 1.11x faster)
• YJIT=OFF : 1.00x - 1.20x faster (dom: 1.20x faster)

[kou]

Thanks.