Add PWR080: Conditionally initialized variables can lead to undefined behavior

[alvrogd]

Add entry and benchmark for a new check. My results:

$ lscpu
  Model name:             13th Gen Intel(R) Core(TM) i7-13700H

$ gcc --version                            
gcc (Ubuntu 13.3.0-6ubuntu2~24.04) 13.3.0

$ gfortran --version                                                 
GNU Fortran (Ubuntu 13.3.0-6ubuntu2~24.04) 13.3.0

$ ./run-benchmarks.py --check PWR080
------------------------------------------------------------------
Benchmark                        Time             CPU   Iterations
------------------------------------------------------------------
PWR080 C Example               560 us          560 us         1235
PWR080 C Improved              559 us          559 us         1244
PWR080 Fortran Example         558 us          558 us         1254
PWR080 Fortran Improved        561 us          561 us         1242

[daniel-otero]

LGTM.

[ruifm]

I disagree this is a good example solution: PWR080 should be about the unitialized variable factor alone, it should not bother with another variable like option and worry if all it's possible values are properly checked, that is foreign to the real issue.

The simplest solution (and the one that would allow linting tools to produce autofixes for PWR080) would be to just initialize factor in it's declaration to avoid potential undefined behavior. Whether the value chosen is "correct" or not, is also besides the point, which is to turn undefined behavior into consistently defined behavior.

[ruifm]

Also: #103 (comment)

[alvrogd]

I disagree this is a good example solution: PWR080 should be about the unitialized variable factor alone, it should not bother with another variable like option and worry if all it's possible values are properly checked, that is foreign to the real issue.

That's a good point of view! I've updated the solutions to suggest the default initialization of factor.