[llvm] [Support][Casting] Add predicates for `isa*` functions (PR #83753)

[David Blaikie via llvm-commits]

dwblaikie wrote:

It'd probably be an issue for some callers, but we could make the actual `isa`, etc into functors so we don't need to introduce new names? Something like this: https://stackoverflow.com/questions/62928396/what-is-a-niebloid (not in this case to thwart overloading, but to make it easy to pass as functors)


https://github.com/llvm/llvm-project/pull/83753