[llvm] [InstCombine] Fix for folding `select` into floating point binary operators. (PR #83200)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> > Testcase for this?
> 
> @arsenm I'm using the following code (compiled with `-fopenmp`) for testing this: https://github.com/dslarm/Financial-Services-Workload-Samples/blob/main/MonteCarloEuropeanOptions/MonteCarloInsideBlockingDP.cpp

Can you turn this into a reduced IR test, in a PR with your proposed patch above 

https://github.com/llvm/llvm-project/pull/83200