[clang] [llvm] [Matrix] Implement matrix support for the `select` intrinsic (PR #227753)

[Tom Stellard via llvm-commits]

tstellar wrote:

@kmpeng It looks like there was an issue merging this PR and it ended up creating two commits upstream.  This is not your fault, but I'm wondering if you saw any error messages or anything when you merged it?

https://github.com/llvm/llvm-project/pull/227753