[llvm] [IPSCCP] Variable not visible at Og. (PR #66745)

[Carlos Alberto Enciso via llvm-commits]

CarlosAlbertoEnciso wrote:

@nikic I am happy to move the new logic to some generic location as
```
DIExpression *convertConstantToExpression(const Constant *CV)
or
DIExpression *getExpressionForConstant(const Constant *CV)
```
@llvm/pr-subscribers-debuginfo @llvm/issue-subscribers-debuginfo any suggestions?

https://github.com/llvm/llvm-project/pull/66745