See https://github.com/llvm/llvm-project/pull/147168 for more info.

See https://github.com/llvm/llvm-project/pull/147168 for more info.

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.

This fixes the following failure when doing a clean build (in particular
no .ninja* lying around) of lib/libMLIRControlFlowToSCF.a only:
```
In file included from llvm/include/llvm/IR/Module.h:22,
                 from mlir/include/mlir/Dialect/LLVMIR/LLVMDialect.h:37,
                 from mlir/lib/Conversion/ControlFlowToSCF/ControlFlowToSCF.cpp:19
llvm/include/llvm/IR/Attributes.h:90:14: fatal error: llvm/IR/Attributes.inc: No such file or directory
```

This reverts commit 43b508566799751aa180f1eaaafc5be693f2f1ae since it
caused the build to break with BUILD_SHARED_LIBS=ON.

This change removes dependencies declared as either 'LINK_LIBS' or
'LINK_COMPONENTS' across several MLIR libraries. The removed
dependencies appear
to be incorrect and may have been required in older versions of the
project.
These dependencies cause many high level dialects to have transitive
dependence on the LLVM dialect and the LLVM 'Core' library
('llvm/lib/IR').

Note that if using the 'Ninja' CMake generator, one can inspect the
dependencies
(including all transitive libraries) of any given MLIR target but using
the command `ninja -C <build dir> -t browse` and navigating to the
library
of interest in a web browser.

When creating a new block in (conversion) rewrite patterns,
`OpBuilder::createBlock` must be used. Otherwise, no
`notifyBlockInserted` notification is sent to the listener.

Note: The dialect conversion relies on listener notifications to keep
track of IR modifications. Creating blocks without the builder API can
lead to memory leaks during rollback.

This is useful when user already have partially-scf'ed IR or other ops with nested regions (e.g. linalg.generic).

Also, improve error message and pass docs.

Differential Revision: https://reviews.llvm.org/D158349

This is a follow-up to https://reviews.llvm.org/D156889

Downstream projects may have more complicated ops than the control flow ops upstream and therefore need a more powerful interface to support the lifting process. Use cases include the propagation of (inherent) metadata that was previously on the control flow ops and now needs to be lifted to structured control flow ops.
Since the lifting process is inherently non-local in respect to the function-body, we require stronger guarantees from the interface.

This patch therefore makes two changes to the interface:
* Passes the terminator that is being replaced to `createStructuredBranchRegionTerminatorOp`
* Adds as precondition to `createCFGSwitchOp` that its predecessors are already correctly established

Asserts have been added to verify these were it makes sense and to correctly state intent. I have not added tests purely because testing preconditions like these is not really feasible (and incredibly specific).

Differential Revision: https://reviews.llvm.org/D157981

This is useful for any downstream users who may just want to use slightly different ops than the pass or need to take into account other ops in the input while still dealing with ControlFlow ops for the most part.
This also helps writing test implementations for `transformCFGToSCF`.

Since the implementation is now public, comments noting the post conditions of the methods have been added to ensure downstream users can stay compatible with the existing implementation.

Differential Revision: https://reviews.llvm.org/D157971