Adopt `ArrayRef::consume_front()` in `PrintMessage`, and convert the
loop in that function to a range for loop.

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

This patch adds an even more aggressive short-circuit on `!and` and
`!or` that completely avoids the evaluation of RHS operand until short
circuiting decisions are made.

These are identified by misc-include-cleaner.  I've filtered out those
that break builds.  Also, I'm staying away from llvm-config.h,
config.h, and Compiler.h, which likely cause platform- or
compiler-specific build failures.

Without this patch the !subst in the test drops the name "$frag" from
(one_frag:$frag ...) and returns:

```
(set FPR32_NEW:$dst, (one_frag FPR32_NEW:$a, FPR32_NEW:$b))
```

This way the dump output is roundtripable.

- Use ArrayRef instead of const vector reference.
- Use range for loops with enumerate and structured bindings.

Rename `ListInit::getValues()` to `getElements()` to better match with
other `ListInit` members like `getElement`. Keep `getValues()` for
existing downstream code but mark it deprecated.

Initialize vectors using constructor instead of llvm::append_range when
possible.

- Add `DagInit::get` overloads that do not need ValName to be specified.
- Fix some calls to either not create temporary arrays for DAG args or
use the std::pair<> overload.