- Use `ArrayRef` instead of `SmallVector` reference in a few places.
- Drop redundant `llvm::` in a few places.

- Also eliminate unneeded std::string() around some literal strings.

If the SDNode is used it can pick up the wrong results number, for
example looking at the known bits of the first result where it should be
looking at the second. The SDValue is already present as the
SelectCodeCommon checks move from parent to child, pass the SDValue
through to CheckNodePredicate as Op so that it can use it if necessary.
SDNode *N is still generated, keeping most PatFrags the same.

Fixes #137274

#125983

These properties are only valid on ComplexPatterns. Having them as flags
is more convenient because one can now use "let = ... in" syntax to set
these flags on several patterns at a time. This is also less error-prone
as it makes it impossible to specify these properties on records derived
from SDPatternOperator.

Pull Request: https://github.com/llvm/llvm-project/pull/119599

Print what result number the Emit* nodes are storing their results in.
This makes it easy to track the inputs of later opcodes that consume
these results.

Change CodeGenDAGPatterns to use const RecordKeeper.

This is a part of effort to have better const correctness in TableGen
backends:


https://discourse.llvm.org/t/psa-planned-changes-to-tablegen-getallderiveddefinitions-api-potential-downstream-breakages/81089