[llvm] [SelectionDAG] Add support for extending masked loads in computeKnownBits (PR #115450)

[Paul Walker via llvm-commits]

https://github.com/paulwalker-arm approved this pull request.

As mentioned on https://github.com/llvm/llvm-project/pull/115142, I don't think the existing handling (or documentation) of the passthru parameter is strict enough to reinforce the assumption in the commit message. I do agree with your interpretation though.

https://github.com/llvm/llvm-project/pull/115450