For the web, we allow a wobbly UTF-16 encoding (i.e. lonely surrogates
are permitted). Only in a few exceptional cases do we strictly require
valid UTF-16. As such, our `validate(AllowLonelySurrogates::Yes)` calls
will always succeed. It's a wasted effort to ever make such a check.
This patch eliminates such invocations. The validation methods will now
only check for strict UTF-16, and are only invoked when needed.
This reverts commit c14173f651. We
should only annotate the minimum number of symbols that external
consumers actually use, so I am starting from scratch to do that
These properties are always substrings of the RegExp input string,
and so we can store them as views and lazily construct strings if
they're actually accessed (which most of the time they aren't).
This avoids a bunch of unnecessary memory copying, saving roughly
2.1 seconds per iteration of Speedometer.
