[llvm] [GlobalISel] emit G_BITCAST in widenScalarUnmergeValues when SrcTy is float (PR #204541)

[Kacper Doga via llvm-commits]

https://github.com/varev-dev commented:

overall LGTM
cc @petar-avramovic - you reviewed the mirror case for widenScalarMergeValues, could you take a look at this one?

https://github.com/llvm/llvm-project/pull/204541