Does reassigning a value to variable have a performance benefit over creating a new variable?

Question

I know that seems like a broad question, so let's restrict the discussion to primitives like ints.

If I have an algorithm like

int val; 
for(int i = 0; i < arr.Length; ++i)
{
   val = ... // a value I need for this iterate of the loop only, and never outside the loop 
}

does that have a performance benefit over

for(int i = 0; i < arr.Length; ++i)
{
   int val = ... // a value I need for this iterate of the loop only, and never outside the loop 
}

I know that some people consider the second to be more proper, with the reasoning being that you should only define a variable in a scope that uses it. But I've seen both in professional settings. My question is about performance.