D-Programming-Language/dmd — pull request #2299 by WalterBright (2013-07-05 07:21:28+00:00)
Title: optimize sequence of ||

This replaces a sequence of:
```
e == c1 || c == c2 || e == c3 || e == c4
```
with a BT instruction on a bit mask made from c1..c4

There aren't too many cases of this in the wild, but there'll be more when I get to doing this for switches.