Do we need faster regex?

[Richard (Rikki) Andrew Cattermole]

If you import std.regex and do nothing else:

sema1 61ms
sema2 101ms

std.internal.unicode_tables:
sema1 4ms
sema2 100ms

https://github.com/dlang/phobos/blob/master/std/internal/unicode_tables.d



Now for:

```d
auto ctr = ctRegex!(`^.*/([^/]+)/?$`);

// It works just like a normal regex:
auto c2 = matchFirst("foo/bar", ctr);   // First match found here, if any
assert(!c2.empty);   // Be sure to check if there is a match before 
examining contents!
assert(c2[1] == "bar");   // Captures is a range of submatches: 0 = full 
match.
```

toImpl:
sema3 125ms

parseSet:
Sema3 111ms

findAny (child of parseRegex and parseSet):

CTFE 51ms





While there are improvements to be had, I have already done all the big 
ones when I shaved off ~600ms earlier this year.

Gotta love time trace!