[PATCH 3.4] Warn for always-false bitwise ands

[Neil Booth]

John Levon wrote:-

> actually means something else ? What does it mean ? And why is this
> table composed of stuff for the C frontends ? What's the difference
> between mine and  ones like -ansi, -Wformat-missing-attribute,
> -Wno-comment, et al ? Where should they go ?

You're right; I'd forgotten stuff went there too.  How ugly.
Need to push on with my options work.

Neil.