waf: compiler flags, uninitalized variable

[Fred Wright]

On Tue, 29 Jul 2025, Hal Murray via devel wrote:

> Are we missing one?
>
> I had a typo.  I was using an uninitialized variable.  Modern compilers
> didn't complain.  Old ones did.  (I don't set any compiler or loader
> flags.)

What gets checked isn't a monotonic function of the compiler version. 
Testing with as many compilers as possible is a plus.

Usually, you won't get that type of warning unless you enable it.  And 
usually, you only get that type of warning in an optimized compile, since 
the dataflow analysis needed to detect it is part of the optimization 
code.

Fred Wright