Fastest minimum-width integer types and limits macros

[Gunther Nikl <gnikl@xxxxxxxxxxxxxxxxxxxxx>]

Hi!

Is there a special requirement about the value of the limits
macros for fastest minimum-width integers? Eg. would it be legal
to use the limits of a a "signed char" if int_fast8_t is defined
in terms of an int? Or is it required to use the proper limit of
int?

Thank you,
Gunther