* [MLIR] Update MLIR/LLVM repos

* Move MLIR/LLVM repos forward

This includes fix to affine fusion algorithm.

* Fix issues after merge

* Fix lit test

* WIP

* WIP

* WIP

* All ops

* Fix layernorm backprop op name

* WIP: Adding tests

* WIP: Adding LIT parsing/printing tests

* WIP

* Added LSTM cells. Fixed some ops

* All builder tests

* PR fixes

* Fix spacing. Add missing setter to SpaceToDepth

* Update spaceToDepth lit test

* PR fixes

* Build fix

* Another fix

* Fixed optional args

* Init commit to implement interface

*  Add two op interfaces for v0 and v1. Add a unit-test

* Add missing files

* Move test to separate file

* Add Fused Op interface

* Missing files

* style

* fused ops

* Remove V1 ops for now

* Added enum attributes. WIP

* Completed non-experiemntal non-fused-ops

* Add ops_attributes

* Minor fixes

* Minor fixes

* Added enum setting/reading test

* style-apply

* Added attributes tests

* Fix dialect init

* style

* fix typo

* Fix merge errors

* Include file with MLIR on

* Re-organize files. Create MLIR backend classes

* WIP

* Refactored. Code compiles

* Moved context to Runtime class to outlive compilation and execution

* style-apply

* Base Runtime class. Few other modifications

* Minor fixes

* Fixed Runtime::run() to take type-erased pointer

* renamed core compiler

* rename backend compiler

* rename runtime compiler

* PR feedback

* Fix build fails

* WIP

* Fixes

* Increase bitwidth for arg idx attrib

* Minor fixes

* style-apply

* Op decl. No verification

* WIP

* WIP: Add lowerer support

* Code-gen works.

* Added padding support. Needs MLIR fix to work

* Remove Padding support for now

* Fix arrayref init. Disable tests where reshape optimization don't apply

* clean up and style apply

* Address PR feedback

We'll add contrib/mlir/tools directory in subsequent PRs for ngrpah-opt
and other tools.

* [MLIR] Fix naming convention in MLIR files

Add naming convention note per file to state which files should use
nGraph naming convention and which MLIR naming convention and align
naming convention in those files with such a note.

* Remove m-prefix

* WIP

* All but two unit tests passing

* Explanatory comment

* Cleanup

* A bit of cleanup stemming from review comments

* Rewrite to use LoopNestBuilder

* Remove unnecessary check from CompiledKernel

* Removed some dead-ish code I missed

* Switch to camelCase in lowerer.cpp

* Fix assignment of resIndexHandles that was triggering an assert

* Add in some safety checks

* dyn_cast -> cast

* Support MLIR lowering of Relu

* Use EDSC comparison

* style-apply

* Use .inc file for Conversion classes list

* Disable i32 Relu for plaidml

This patch introduces tablegen definitions for element-wise reduction
operations (only definitions, not building/lowering code). This includes
argmin, argmax, min, max, sum, prod, all and any.

From the design point of view, a single base class seems to be enough to
cover all the common ground of these operations. A different base class will
be necessary for avg pool reduction operations.

* Improve verification for unary, binary, cmp and select ops. Refactor .td file to enable that.

It extends dot definition to be able to deal with operands that are not
square tensors. It also fixes a bug in the lowerer related to that.

* [MLIR] Replace MatmulBiasOp with DotOp

We disable CPUFusion if MLIR is enabled to avoid CPU specific ops to be
introduced for now.

* Upgrade MLIR. Several code fixes based on API changes

* Fixes due to DialectConv API changes

* style-apply

* PR fixes

* Move dialect and types to mlir namespace

* PR fixes and some cleanup

* Merge fix

* Enable module verification. Fix FakeInput result type to memref

* style-apply

* Initial td file. Cmake changes

* Move all ops to .td file.

* Added few more opcodes to show-case. Fixed PR feedback

* Remove NG_ prefix of opcode records. Some fixes

* Added some doc

*  Adding back NG prefix

* Bug fix in MLIR gen