[PATCH 1/4] include: Add macro to ignore -Wuser-defined-warnings

[Nick Clifton]

Hi Tsukasa,

> +# if __has_warning ("-Wuser-defined-warnings")

I have not seen __has_warning () before.  Is this a new feature of
recent GCCs and Clang, or am I just behind the times ?

Cheers
   Nick