egcs, RFC: patch for possible -Wmissing-noreturn warning

[Joe Buck]

[ determining whether a function will return ]

> 	Yes, but IMHO, this isn't the halting problem.  Its not
> whether it *will* return but whether its *possible* to return.  Ie,
> what are the exit points of the function?  Does it `return', fall off
> its end or call abort/exit/longjmp/{some other `noreturn' function}?

If we require an exact solution (given any function, can it return?), then
it is equivalent to the halting problem.  But we don't require an exact
solution (if we can't tell whether the function returns or not, we assume
that it returns).