[llvm] [Instrumentation] Fix EdgeCounts vector size in SetBranchWeights (PR #99064)

[Ellis Hoag via llvm-commits]

ellishg wrote:

> > Seems ok, but I'd like to see a test so we don't break this in the future.
> 
> I'm not an llvm developer, so any tips about reducing my C++ reproducer to a minimal llvm reproducer would be appreciated.

There are a few ways to get a minimal reproducer depending on your setup. https://llvm.org/docs/HowToSubmitABug.html

I would first try to get a reproducer with unoptimized IR by invoking clang with `-emit-llvm -S -Xclang -disable-llvm-optzns -o a.ll`. Then you can use `llvm-reduce` to further reduce the IR to a small test case. https://llvm.org/docs/CommandGuide/llvm-reduce.html#example

https://github.com/llvm/llvm-project/pull/99064