This improves type safety and is less verbose. Use SimpleTy only where
an integer is needed like switches or emitting a VBR.

---------

Co-authored-by: Sergei Barannikov <barannikov88@gmail.com>

Identified with modernize-use-using.

Identified with readability-redundant-typename.

Identified with modernize-use-equals-default.

Note that "override" makes "virtual" redundant.

Identified with modernize-use-override.

This patch simplifies construction of iterator_range<T> by using:

  iterator_range<T>(Container &&)

instead of:

  iterator_range<T>(T begin_iterator, T end_iterator)

The pattern optimizations in GlobalISelMatchTable.cpp can extract common
predicates out of pattern alternatives by putting the pattern alternatives into
a GroupMatcher and moving common predicates into the GroupMatcher's predicate
list. This patch adds checks to avoid hoisting a common predicate before
matchers that record named operands that the predicate uses, which would lead
to segfaults when the imported patterns are matched.

See the added test for a concrete example inspired by the AMDGPU backend.

This fixes a bug encountered in #143881.

closes #154331 

This PR addresses all minimum changes needed to compile LLVM and MLIR
with the c++23 standard.
It is a work in progress and to be reviewed for better methods of
handling the parts of the build broken by c++23.

Automated with clang-tidy -fix -checks=-*,modernize-use-default-member-init

Previously PatLeafs could not be imported, causing the following
warnings to be emitted when running tblgen with
`-warn-on-skipped-patterns:`
```
/work/clean/llvm/lib/Target/AArch64/AArch64InstrInfo.td:2631:1: warning: Skipped pattern: Src pattern child has unsupported predicate
def : Pat<(i64 (mul top32Zero:$Rn, top32Zero:$Rm)),
^
```
These changes allow the patterns to now be imported successfully.