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.

Adopt `TrailingObjects` convenience API that was added in
https://github.com/llvm/llvm-project/pull/138970 in LLVM and MLIR code.

Add `llvm::uninitialized_copy` that accepts a range instead of start/end
iterator for the source of the copy.

DenseSet, SmallPtrSet, SmallSet, SetVector, and StringSet recently
gained C++23-style insert_range.  This patch replaces:

  Dest.insert(Src.begin(), Src.end());

with:

  Dest.insert_range(Src);

This patch does not touch custom begin like succ_begin for now.

This was discussed during the original review but I made it stricter
than discussed. Making it a pure view but adding a helper for bytecode
serialization (I could avoid the helper, but it ends up with more logic
and stronger coupling).

This location type represents a contiguous range inside a file. It is
effectively a pair of FileLineCols. Add new type and make FileLineCol a
view for case where it matches existing previous one.

The location includes filename and optional start line & col, and end
line & col. Considered common cases are file:line, file:line:col,
file:line:start_col to file:line:end_col and general range within same
file. In memory its encoded as trailing objects. This keeps the memory
requirement the same as FileLineColLoc today (makes the rather common
File:Line cheaper) at the expense of extra work at decoding time. Kept the unsigned
type.

There was the option to always have file range be castable to
FileLineColLoc. This cast would just drop other fields. That may result
in some simpler staging. TBD.

This is a rather minimal change, it does not yet add bindings (C or
Python), lowering to LLVM debug locations etc. that supports end line:cols.

---------

Co-authored-by: River Riddle <riddleriver@gmail.com>

This patch adds the capability to define dialect-specific location
attrs. This is useful in particular for defining location structure that
doesn't necessarily fit within the core MLIR location hierarchy, but
doesn't make sense to push upstream (i.e. a custom use case).

This patch adds an AttributeTrait, `IsLocation`, which is tagged onto
all the builtin location attrs, as well as the test location attribute.
This is necessary because previously LocationAttr::classof only returned
true if the attribute was one of the builtin location attributes, and
well, the point of this patch is to allow dialects to define their own
location attributes.

There was an alternate implementation I considered wherein LocationAttr
becomes an AttrInterface, but that was discarded because there are
likely to be *many* locations in a single program, and I was concerned
that forcing every MLIR user to pay the cost of the additional
lookup/dispatch was unacceptable. It also would have been a *much* more
invasive change. It would have allowed for more flexibility in terms of
pretty printing, but it's unclear how useful/necessary that flexibility
would be given how much customizability there already is for attribute
definitions.

The MLIR classes Type/Attribute/Operation/Op/Value support
cast/dyn_cast/isa/dyn_cast_or_null functionality through llvm's doCast
functionality in addition to defining methods with the same name.
This change begins the migration of uses of the method to the
corresponding function call as has been decided as more consistent.

Note that there still exist classes that only define methods directly,
such as AffineExpr, and this does not include work currently to support
a functional cast/isa call.

Context:

* https://mlir.llvm.org/deprecation/ at "Use the free function variants for dyn_cast/cast/isa/…"
* Original discussion at https://discourse.llvm.org/t/preferred-casting-style-going-forward/68443

Implementation:
This follows a previous patch that updated calls
`op.cast<T>()-> cast<T>(op)`. However some cases could not handle an
unprefixed `cast` call due to occurrences of variables named cast, or
occurring inside of class definitions which would resolve to the method.
All C++ files that did not work automatically with `cast<T>()` are
updated here to `llvm::cast` and similar with the intention that they
can be easily updated after the methods are removed through a
find-replace.

See https://github.com/llvm/llvm-project/compare/main...tpopp:llvm-project:tidy-cast-check
for the clang-tidy check that is used and then update printed
occurrences of the function to include `llvm::` before.

One can then run the following:
```
ninja -C $BUILD_DIR clang-tidy

run-clang-tidy -clang-tidy-binary=$BUILD_DIR/bin/clang-tidy -checks='-*,misc-cast-functions'\
                 -export-fixes /tmp/cast/casts.yaml mlir/*\
                 -header-filter=mlir/ -fix

rm -rf $BUILD_DIR/tools/mlir/**/*.inc
```

Differential Revision: https://reviews.llvm.org/D150348

The KeyTy of attribute/type storage classes provide enough information for
automatically implementing the necessary sub element interface methods. This
removes the need for derived classes to do it themselves, which is both much
nicer and easier to handle certain invariants (e.g. null handling). In cases where
explicitly handling for parameter types is necessary, they can provide an implementation
of `AttrTypeSubElementHandler` to opt-in to support.

This tickles a few things alias wise, which annoyingly messes with tests that hard
code specific affine map numbers.

Differential Revision: https://reviews.llvm.org/D137374