Add approved TensorPrimitives surface area

[stephentoub]

Adds all of the approved TensorPrimitives surface area from:
#103611
#104117

[dotnet-issue-labeler]

Note regarding the new-api-needs-documentation label:

This serves as a reminder for when your PR is modifying a ref *.cs file and adding/modifying public APIs, please make sure the API implementation in the src *.cs file is documented with triple slash comments, so the PR reviewers can sign off that change.

[dotnet-issue-labeler]

Note regarding the new-api-needs-documentation label:

This serves as a reminder for when your PR is modifying a ref *.cs file and adding/modifying public APIs, please make sure the API implementation in the src *.cs file is documented with triple slash comments, so the PR reviewers can sign off that change.

[dotnet-policy-service]

Tagging subscribers to this area: @dotnet/area-system-numerics-tensors
See info in area-owners.md if you want to be subscribed.

[Copilot]

PR Overview

This PR adds the approved surface area for TensorPrimitives by introducing a variety of new element‐wise operations (e.g. average, is complex, is finite, bitwise and arithmetic increments/decrements, division with remainder, and clamping) for numeric tensors. Key changes include the implementation of new static methods in TensorPrimitives for common numeric operations, the introduction of vectorized operator overloads, and several overloads to support both span and scalar inputs.

Reviewed Changes

File	Description
TensorPrimitives.Average.cs	Adds a method to compute the average of elements.
TensorPrimitives.IsComplexNumber.cs	Adds methods for checking complex number properties.
TensorPrimitives.IsFinite.cs	Implements methods to check finiteness with vectorized operations.
TensorPrimitives.BitDecrement.cs	Provides bit decrement functionality.
TensorPrimitives.IsEvenInteger.cs	Introduces methods for identifying even integral numbers.
TensorPrimitives.ConvertToIntegerNative.cs	Implements platform-specific native conversion to integer.
TensorPrimitives.IsCanonical.cs	Adds canonical form checks with vectorized shortcuts.
TensorPrimitives.ConvertToInteger.cs	Implements saturating integer conversion.
TensorPrimitives.BitIncrement.cs	Provides bit increment operations.
TensorPrimitives.Increment.cs	Adds element-wise increment functionality.
TensorPrimitives.Decrement.cs	Adds element-wise decrement functionality.
TensorPrimitives.DivRem.cs	Implements division with remainder for spans and scalars.
TensorPrimitives.Clamp.cs	Provides multiple overloads for clamping tensor values.

Copilot reviewed 45 out of 45 changed files in this pull request and generated 3 comments.

Tip: If you use Visual Studio Code, you can request a review from Copilot before you push from the "Source Control" tab. Learn more