Updated the generated code to cope with big Widths.

Updated the generated code to cope with big Widths (>32 bits) on 32 bit
processors.
Since C89 does not give a way to specify the minimum length of a data type,
the test does not validate C89 code using Widths > 32.
For C99, the uint_fastN_t data types are used or long long, if the Width is
unknown.