[Executorch] Add broadcasting support to optimized op_sub (#8256)

* [Executorch] Refactor op_mul's broadcasting utils

Summary:
Refactoring broadcast handling utils that were added for op_mul. This is
in prepartion use these utils to handle broadcast for other ops such as
add, sub, div.
Plus remove a redundant test

Test Plan:
optimized_kernels_test in CI

Reviewers:

Subscribers:

Tasks:

Tags:

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* [ExecuTorch] Add broadcast support for optimized add op

Summary:
This brings add op to feature parity, wrt, broadcasting, to mul op in
optimized kernels lib

Test Plan:
tests added

Reviewers:

Subscribers:

Tasks:

Tags:

[ghstack-poisoned]

* Update on "[ExecuTorch] Add broadcast support for optimized add op"


Summary:
This brings add op to feature parity, wrt, broadcasting, to mul op in
optimized kernels lib

Test Plan:
tests added

Reviewers:

Subscribers:

Tasks:

Tags:

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* [Executorch] Refactor op_add to support op_sub broadcasting

Summary:
Refactor op_add to conslidate commong broadcasting related improvements

Test Plan:
Previously added tests

Reviewers:

Subscribers:

Tasks:

Tags:

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* [Executorch] Add broadcasting support to optimized op_sub

Summary:
This diff builds on top of previous one to add support for limited
handling of broadcasting for sub

Test Plan:
tests added

Reviewers:

Subscribers:

Tasks:

Tags:

[ghstack-poisoned]

* Update base for Update on "[Executorch] Add broadcasting support to optimized op_sub"


Summary:
This diff builds on top of previous one to add support for limited
handling of broadcasting for sub

Test Plan:
tests added

Reviewers:

Subscribers:

Tasks:

Tags:

cc larryliu0820 manuelcandales

[ghstack-poisoned]

* Update base for Update on "[Executorch] Add broadcasting support to optimized op_sub"


Summary:
This diff builds on top of previous one to add support for limited
handling of broadcasting for sub

Test Plan:
tests added

Reviewers:

Subscribers:

Tasks:

Tags:

cc larryliu0820 manuelcandales

[ghstack-poisoned]

* Update base for Update on "[Executorch] Add broadcasting support to optimized op_sub"


Summary:
This diff builds on top of previous one to add support for limited
handling of broadcasting for sub

Test Plan:
tests added

Reviewers:

Subscribers:

Tasks:

Tags:

cc larryliu0820 manuelcandales

[ghstack-poisoned]

* Update base for Update on "[Executorch] Add broadcasting support to optimized op_sub"


Summary:
This diff builds on top of previous one to add support for limited
handling of broadcasting for sub

Test Plan:
tests added

Reviewers:

Subscribers:

Tasks:

Tags:

cc larryliu0820 manuelcandales

Differential Revision: [D69491818](https://our.internmc.facebook.com/intern/diff/D69491818)

[ghstack-poisoned]

* Update base for Update on "[Executorch] Add broadcasting support to optimized op_sub"


Summary:
This diff builds on top of previous one to add support for limited
handling of broadcasting for sub

Test Plan:
tests added

Reviewers:

Subscribers:

Tasks:

Tags:

cc larryliu0820 manuelcandales

Differential Revision: [D69491818](https://our.internmc.facebook.com/intern/diff/D69491818)

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