[Any extended integer types that exist in the implementation (6.2.5).]
[Whether signed integer types are represented using sign and magnitude,
two's complement, or one's complement, and whether the extraordinary value
is a trap representation or an ordinary value (6.2.6.2).]
GCC supports only two's complement integer types, and all bit patterns
are ordinary values.
[The rank of any extended integer type relative to another extended
integer type with the same precision (6.3.1.1).]
[The result of, or the signal raised by, converting an integer to a
signed integer type when the value cannot be represented in an object of
that type (6.3.1.3).]
[The results of some bitwise operations on signed integers (6.5).]
