* Release notes 0.26.0-rc.3 and revise bridges overview

* Fix version module and add latest release notes; update some doc menus

* Let release notes be discoverable

* Documentation master index

* Documentation index pg

* Update ops for version

* Update illustration

* Remove old illustration

* Add note for 0-rc.4

* Add section on NGRAPH_PROFILE_PASS to backend API

* rc-0.5

* Final preview 0.26 release notes

* Note changes on Sum validation

* Fix link syntax that breaks on Sphinx 3.0

* Revert file that triggers unnecessary review

* Typo fix

* PR feedback

* Consistency on section title capitalizations

* Update link

* Section title consistency

* Implemented downgrade pass

* Using Pad:v1 in onnx_importer

* Downgrade transformation doc fixed

* Downgrade pass added for all backends

* Apply suggestions from code review

Changed pad_opset_pass to opset_downgrade
Co-Authored-By: Tomasz Socha <tomasz.socha@intel.com>

* Changed order of passes

* Changed downgrade pass order of CPU backend

* Added reverse:v1 downgrade

* Code review remakrs introduced

* Fixed problem with foward declaration

* Modify convert op to convert from bf16 to float and vice-versa

* Add a check

* Remove conversion routines and use the convert op for casting

* disable unit tests for plaidml

* add get_default_pipeline_depth to executable

* use get_preferred_pipeline_depth

* Cyphers/lastwarns (#3640)

* Build changes for -Wall

* Use properties

* Remove no-zero-as-null-pointer-constant

* add ##__VAR_ARGS__ workaround

* enable gnu-zero-variadic-macro-arguments warning

* fix gnu-zero-variadic-macro-arguments

* use PrintToDummyParamName

* remove ##__VA_ARGS__ workaround

* fix ##__VA_ARGS__ and enable gnu-zero-variadic-macro-arguments

* handle windows build

* use alternative fix to support VS compiler

* fix merge issue

* remove variadic macros from kernel_selectors

* replace remaining ##__VA_ARGS__

* fix missing braces

* Remove some clang warnings

* Warnings cleanup

* Switch op dynamic casts that crept back in

* PR for debugging purposes (#3718)

* back out

* transpose

* next try

* Another is_type

* Another is_type

* next is_type

* Revert, is_type remainder

* verify

* v1 and Dyn mixup

* Work around clang++-3.9 bug

* Implemented downgrade pass

* Using Pad:v1 in onnx_importer

* Downgrade transformation doc fixed

* Downgrade pass added for all backends

* Apply suggestions from code review

Changed pad_opset_pass to opset_downgrade
Co-Authored-By: Tomasz Socha <tomasz.socha@intel.com>

* Changed order of passes

* Changed downgrade pass order of CPU backend

* Code review remarks introduced

* add check for dynamic dimensions

* to_shape() -> rank()

* Delete unnecessary check

* Added in DeduceDynSlice suite to check dynamic dimension

* minor codestyle fix

* c-cast -> static_cast

Remove Intel GPU backend

* Added power constant folding

* Style apply

* Removed python operator pow

* Hotfix for negative axes in unsqueeze op (#3705)

* Hotfix for negative axes in unsqueeze op

* Review fix I

* Enable Gather with negative indices. (#3701)

* Enable Gather with negative indices.

* Address PR feedback.

* Remove GOE from Gather unit tests.

* merge error

* Disable test for MLIR

* More expressive error messages

* style

Enable in place rotation for Reshape for blocked data format.

* Added ReduceMean, ReduceMin, ReduceMax; Updated ReduceProd, ReduceSum

* Removed redundant method from arithmetic_reductions_keep_dims.cpp

* Fixed code style issues

* Removed generate_adjoints

* Fixed cpu_emitter

* [ONNX] Remove broadcasting from ONNX importer.

* [ONNX] Used Xor op instead of And,OR and NOT ops.

An optional optimization level was added to ExecutionEngine, initialized
to None by default. This caused fast-isel to be used in LLVM CG,
overriding all the flags related to not using fast-isel.

In this PR we pass the right optimization level to ExecutionEngine.

* Fix ops, cleanup ToC, add latest illustrations

* PR feedback

* Support non-mkldnn fallback for Batchnorm training bprop in CPU backend

* Skip unit test on PlaidML backend

* Change method of splitting data and filters for groups

* Add support for groups included in filters shape

* Add UT for groups in weights shape

* Add helper function to check if groups are in filters shape

* Review fix I

* Remove unused variables

* Skip test on PlaidML

* Review Fix II

* Internaly store groups as dimension instead of size_t

* Review fix III

* Add updating of m_groups in pre_validate_and_infer_types()

* Provenance for builders (#3644)

* Provenance for builders

* Tests

* Tests

* Update src/ngraph/node.hpp
Co-Authored-By: Sayantan Sarkar <sayantan.sarkar@intel.com>

* style

Finish migration

* Migration to master

* Handle op constructors that construct ops

* Update provenance for topk

* Add missing input (#3691)

* Add missing input

* If builder does nothing, don't dive into the inputs

* Reverse test

* simplify, add test

* Add test

* add test

* Add RandomUniform op

* Missing files

* Make CPU compile again (RandomUniform tests still don't pass)

* Bop users of existing RNGState class and reorder some comment junk

* Try to bop RNGState in gcpu

* Add RandomUniform to CPU manifest

* Add RandomUniform to PlaidML manifest

* Add .rst for random_uniform

* Clean up junk in the .rst

* Change UniformRNGState to always use double internally

* Change weird test failure message

* RandomUniform implementation for CPU backend

* Add missing file

* Add codegen support

* Code cleanup

* Address review comments

* Fix CI failure

* Fixed CI error

* Fixed CI error

* [MLIR] Add support for parsing nGraph tensor type

Initial commit that enables nGraph parsing. It's needed for testing.

* [MLIR] Enable nGraph dialect in ngraph-opt

This PR registers nGraph dialect in ngraph-opt and prepares
nGraph lowering pass for LIT testing, fixing all the related issues.
Among other things, lowering pass has to be turned into a function pass,
dead argument in constructor was removed and `convert-ngraph-to-affine`
flag was added.

* Fix issue with function name and multiple functions

* Extend module_function.mlir lit test

* [MLIR] Add support for parsing nGraph element types

It introduces initial support for parsing nGraph signed/unsigned
integer and floating point data types.

* [MLIR] Improve gather op lowering

This PR interchanges indices and param loops in gather lowering so
that a better memory access patter is generated. Fusion of gather
with other ops is also observed with this change.