Patch -Wtraditional, warn about `U' integer constant suffix

[Richard Earnshaw]

ghazi@caip.rutgers.edu said:
> SunOS4, which I use as a benchmark, supports `L'.  However I've
> noticed in the past it has supported some extensions, e.g. void*. I
> don't know whether all K&R compilers grok `L' or not. 

OK, time to put this issue to bed...

K&R - The C Programming Language, Appendix A (page 180):

2.4.2 Explicit long constants

A decimal, octal, or hexadecimal integer constant immediately followed by 
l (letter ell) or L is a long constant.  ...

R.